Because of the optional nature of several of the rules, previous methods of adding versatility to humans, like skill trainings and feats won't work. So you're pretty much left with giving them a leg up in an area that they know will be used at every table...attributes checks. I guess they could bring back level limits, but I doubt that would be popular.
Now, because you can't use feats or skill training to express these things (because a portion of your base may not use those modules), what's left that lets a human be whatever they want to be, have skills outside their profession, multiclass easily, and hard to take down because of good saves?
...
+2 to one ability score, +1 to the other five. It's actually the simplest, most basic, and elegant way to mechanically represent the narrative fluff of the D&D human throughout every edition of the game.
As I mentioned in my previous post, ability scores is not the only thing that's left.
What would be more acceptable for D&D gamers between humans being genetically better than all other common races (the effective +1 to all stats) and being faster at progressing through levels (an XP bonus)?
For me the XP bonus is more acceptable, and personally I would find it quite a lot in tune with at least the older editions and 3ed!
Because in old D&D Elves are Elves true... and practically they are Fighters and Wizards at once, which sounds straight better than humans. But... they have a slower advancement rate (not in the form of XP bonuses but the other way around, higher XP required to level up).
And in 3ed demihumans (except Half-Orcs) get a +2 and -2, which mathematically cancel out
but every player knows that the +2 weights more because you are going to put it where you need it while you can mitigate the effect of -2
and that +2 can take you up to 20 when humans can never be more than 18 (at 1st level of course). Multiclassing for humans is easier so theoretically a demihuman would more easily get an XP penalty from a non-optimal multiclassing combination, but practically this is a non-issue since almost nobody ever makes such choice in 3ed.
Still, overall at least in those editions I'm more familiar with, the
feeling for me has always been "elves, dwarves etc. are genetically better than humans" (perhaps some relic of Tolkien ideas) but can be sometimes slower at advancing... which actually matches with their longer lifespans.
