I agree that limitations are good. You seem to want more hard-coded limitations than I do, and you seem to want them for everyone who plays the game, not just you and yours, for...reasons?
I don't really care what the specific limitations in the books are, because I'm going to change them for my games anyway.
I just don't want the
structure and the
precedent of those limitations to be further eroded. I mean,
given my preferences, ancestry would be a much more substantial portion of character abilities-- from first to cap-- the majority of ancestry options wouldn't be subrace-locked, and ancestries would have restrictions on their available classes (less strict but more varied than AD&D) and multiclass combos. Lost that fight before I slapped leather, but I would really like to keep
even more of the narrative and mechanical weight of ancestry from being removed into
another practically meaningless choice at 1st level.
Doing "something".
In the old editions elves only had better senses, resistance to charms, immunity to sleep because it had to be balance to a human who had... nothing for a while.
When they gave some elf subraces "something" like spells, they were forced to give them harsh penalties as balance to square up with humans.
Let's say that Elves get a Fighting Style and their own half-caster progression. I don't like
darkvision on surface elves, but let's stick with it for the sake of argument. Fast land movement. Fey resistances. That's your first level. Every X levels, you can improve your elf vision (+ Perception/Investigation, darkvision radius, come up with something), your elf hearing (blindsense), your elf mobility (land speed, eladrin teleport), or maybe your elf martial stuff (extra attack) or your elf spellcasting.
Dwarves get Medium Armor, bump their Hit Die up a step, darkvision, and their poison and magic resistance. Maybe they get Heavy Armor. Remove the "dim light" penalty for darkvision. Tremorsense. Resilient saves, other damage resistances,
extra Hit Dice. Crafting? More... armor... stuff.
Humans don't get
unique human stuff; they get more picks for generic stuff. Human ancestry widgets can be used on class/multiclass widgets, humans can multiclass
more better than nonhumans, humans get more proficiencies and fighting styles and
whatever than everyone else.
If we keep "subraces" as a thing, you pick it at 1st and maybe each subrace has a few unique ancestry widgets, but most of your ancestry widgets are chosen freely from your general ancestry list. Because "subraces" aren't as different as actual ancestries.