There is a long history in D&D (and other games with multiple races/species) of treating humans as the vanilla race, into which new flavors could be mixed to produce other races.

In the early days, humans literally got nothing: other races got bonuses and hopefully flaws that cancelled them out (realistically, this meant that there was probably at least one race that was better than humans for any build; the build could use that race’s bonus but mostly ignore the flaw).

These days, it’s common to try to give them some kind of versatility advantage (e.g., a choice of trait bonus, feat/edge, etc.). That’s mechanically better (there are now often builds for which human is only slightly weaker than the best choice race), but it’s still treating humans as vanilla: there’s nothing much about their racial traits that says anything about them. Every other race is more or less a pre-specialized human, so anything that applied to humans would apply to other races by thematic inheritance.

I’ve noticed some interesting memes over the course of the last couple of years that aim to fix that: what if human capabilities are not universal? Rather than being a chassis onto which other race options add, humans have special abilities that are implicitly removed from other races. If humans are the toughest race in space, what does it mean that every other race is less durable than humans? If they’re the most loyal, what does that say about other races’ social dynamics?

This is a neat way to go, and immediately more interesting than vanilla humans, but it can result in some weirdness. If you give humans a couple of things that they’re paragons at, you can limit your race design conceptually. In particular, while the “humans as space orcs” meme is very neat, it means you can’t make actual space orcs; all your proud warrior race guys wind up squishier than humans (admittedly, Farscape did interesting things with this with the Luxans’ difficulty clotting and Sebaceans’ difficulty regulating body temperature).

And, at its core, the whole thing goes back to roleplaying hooks: turning pieces of the human experience into special abilities is a mechanical way to make players portraying non-humans think of their characters as not humans in funny prosthetics. It’s a piece of your lived experience that you can’t just take for granted for your character.

It also has a neat effect on the overall thematic space of the campaign/setting: by designating a human trait as significant enough to qualify as a racial advantage, you’re saying that trait or its absence is meaningful world context. If humans are extremely loyal, and other races are not, that’s an immediate crux around which to pivot your politics and societies.

I think it’s possible to split the difference between vanilla and paragon and still get a good result.

The trick is to call out 3-5 racial advantages for humans. Near-human races swap out one or two of those advantages for something else. Strange races swap out nearly all of them (but likely keep one just for the ability to run mirror-darkly stories around the one similarity highlighting the differences).

For example, in a D&D 5e game based on the same strengths in the linked memes, I might do something like this (I don’t know if these racial benefits are remotely balanced for 5e; they’re mostly set as illustrations of the concept):

Human Traits

Humans bond deeply to companions, including animals and even inanimate objects, and are happy to risk their own lives to protect these others. But this risk is less than that of many other races: they shake off injuries that would permanently cripple others, and recover quickly (even if the scar tissue isn’t always pretty). The coupling of their short lifespans and bonding results in multiple very different cultures, and mixed parentage that means any human might be born with a natural talent for any given pursuit.

  • Recklessly Loyal: As a bonus action, designate a named target (including inanimate objects) that you have spent enough time with to feel loyal to (GM’s discretion as to how much time this takes). You gain Advantage on attack rolls against subjects that are directly threatening your target and on ability checks made to directly rescue the target from harm (again, GM’s discretion on what “directly” means). You may use the Protection fighting style to benefit your target, even if you are not wielding a shield. While active, you are overly focused on protecting your target and thus have Disadvantage on Dexterity saving throws and all attacks against you are made with Advantage. You can deactivate this or switch targets as another bonus action, and it ends automatically when you are rendered unconscious. You may only maintain one target at a time.
  • Bent but Not Broken: Any time you would be Charmed, Frightened, or Stunned, you may take a level of Exhaustion instead (this requires your reaction). You gain advantage on saving throws against any effect that would apply Poisoned. You gain Advantage on all saving throws if your current hit points are less than half your maximum hit points.
  • Life is Too Short: Any time you would recover hit points, recover +1 HP per die of healing rolled. You recover an additional level of Exhaustion per long rest. If you are suffering from any other detrimental effect that persists through a long rest, you recover from it at twice the normal rate.
  • Endless Variety: You gain two languages of your choices in addition to Common. Increase any ability score by +1, or choose an extra skill proficiency. Increase any ability score (except one you chose to raise by +1) by +2, or choose an extra Feat. (The options in this feat may be pre-selected by particular subrace/culture options.)

Dwarf Traits

Due to their long lives, dwarves do not share the rapid recovery of humans nor the cultural variety: they are more set in their ways, prone to long consideration, and find it hard to adapt their politics to new ideas. However, they do have a similar ability to bond to others (but are more likely to use it on close family than on friends) and an even more significant case of stubborn refusal to submit to injury.

  • Recklessly Loyal: As the Human trait; Dwarves are most likely to use this on family/clan members and on inanimate objects that they consider sacred.
  • Bent but Not Broken: As the Human trait; Dwarves are, if anything, more stubborn than Humans.
  • Deep Dweller: Accustomed to living underground, you have superior vision in dark and dim conditions; within sixty feet of you, treat the lighting condition as one step brighter (but, when treating darkness as dim light, you can only see in black and white). Additionally, whenever you make an Intelligence (History) check related to the origin of stonework, you are considered proficient in the History skill and add double your proficiency bonus to the check (instead of your normal proficiency bonus).
  • Children of the Smith: Increase your Constitution score by 2 and your Strength or Wisdom score by 1. You have proficiency in all axe and hammer weapons and with one set of artisan’s tools of your choice.

Elf Traits

Elves live extremely long lives, and value their own very highly. They do not share the strong bonds of humans; it takes a long time to gain the full love and trust of an elf, and even then it is hard for her to risk her own life to save yours. Neither do they share the resilience and recovery of the shorter-lived; elves make it a point to use grace, wit, and craft to avoid being injured at all, for wounds may stick with them for uncomfortably long periods. Strangely, they do share in the variety of humanity, seeming to possess a natural tendency to adapt to the environments.

  • Endless Variety: As the Human trait; Elves are particularly likely to have these choices pre-selected by a subrace.
  • Superior Training: Due to your long life, you’ve picked up several tricks. You have proficiency in the Perception skill and with four martial weapons. Additionally, gain a cantrip or some other special lore (such as increased speed and hiding ability in the wilderness). These choices are likely to be pre-selected by a subrace.
  • Blood of the Ancients: Accustomed to twilit forests and the night sky, you have superior vision in dark and dim conditions; within sixty feet of you, treat the lighting condition as one step brighter (but, when treating darkness as dim light, you can only see in black and white). Additionally, you have advantages on saving throws against being charmed. Magic cannot put you to sleep, and instead of sleeping you enter a meditative trance for four hours a day (gaining the same benefits that a Human does from eight hours of sleep).
  • Subrace: You have a tightly knit family that favors you above outsiders; gain advantage on all Charisma (Persuasion) and Wisdom (Insight) checks when dealing with other members of your subrace. Your particular subrace provides suggested choices for your Endless Variety and Superior Training traits.

Halfling Traits

Halflings are, in many ways, humans writ small. They share many things in common with their bigger cousins, except for their particular indomitable ruggedness in the face of injury. Instead, they possess their own form of courage and luck.

  • Recklessly Loyal: As the Human trait; Halflings are less likely to protect inanimate objects, and more likely to protect dear friends.
  • Life is Too Short: As the Human trait; though they are slightly longer-lived than Humans, Halflings still recover from injury much more quickly than the elder races.
  • Endless Variety: As the Human trait; Halflings tend to favor Dexterity more highly than Humans, but otherwise have nearly as much variety.
  • Small Body, Giant Heart: You are Small, and your base walking speed is 25 feet, but you may move through the space of any creature that is of a size larger than yours. The courage and luck of larger folk are concentrated within you: you have advantage on saving throws against being frightened, and can reroll any attack roll, ability check, or saving throw when you roll a 1.