The problem is that if you start gating important elements of a species behind feats (or something similar) then people will declare it a feat tax. Especially if it's something important like flight or large size or similar.
If some parts of those features are too powerful for first few levels(flight, usage of a 3rd level spell) that is a good way to have that gated behind a feat.
It can also describe in RP terms that you maybe posses a special genetic trait that is rare in your species.
Or is just too much for a "species budget" comparing to other species.
but, maybe the biggest problem in 5E is common pool for all types all feats and ASIs.
maybe it should be 3 pools:
Combat feats, non-combat feats, ASIs.
also idea that I have is that some species are just templates.
and you get them via 1st level feat(maybe later if it's RP appropriate).
1st: buff up 1st level feats to a "strong" full feat that you would like to take at 4th level without attached ASI and not feeling robbed.
then turn Aasimars, tieflings, warforged, shifters, dhampirs, etc... into 1st level feats.
with added 4th level upgrade with +1 ASI if needed or if it's too much for a 1 feat budget.
then you can have difference betweem human aasimars, and elven aasimars, elven tieflings(fey'ri) and orc tieflings, gnome warforged or human worforged, orc dhampirs or dwarf dhampirs. In both RP terms and mechanics.
Ofc, this can also be used for "half-species".
you get: Elven touched feat. and gain some or all elven features on your non elven species, making you a half elf.
also, I like the idea if A5E of later level species power, but it is too late and not that powerful, 5th level would be more appropriate so maybe all campaigns see those features.