With the usual caveat of not having seen the full picture...
I'm pretty much disappointed with all of them.
Dragonborn is an upgrade from 2014, but Fizban 's versions are better.
Dwarf trades all their extra abilities for .. a few minutes of tremorsense. RIP mountain dwarf.
Halflings are just all light feet now. RIP stout.
Goliaths lost athletes. Orcs lost powerful build.
Aasimar can change their celestial choice whenever, but gnome, elf, tiefling and goliaths still have subraces (I'm sorry, lineages).
Elf is a travesty. Apparently the trance proficiencies are gone, subraces are three bonus spells and you get a choice of three proficiencies (who are we kidding, perception is the best one).
Also, RIP to all the "subraces" that weren't in the core books. You're either so much better than the core race options or no longer usable. RIP ghostwise halflings, sea elves, eladrin, shadar-kai, duergar, snirfneblin, variant tieflings and Fizban dragonborn.
Oh, and pour one out for the half elf and half orc. Told you there would be no replacement system. Hope the DMG has more info, but not counting on it.
For all the praise I have for the revisions to the classes, I have as much disdain for their handing of species. Monsters of the Multiverse was perfection; they just needed to add the PHB species in that style and they would be great. But I wager we'll get a revised MotM soon so they can beat the everliving hell out of those species too.