Indeed, doing away with subspecies appears to have been a goal of the 2024 species redesigns. They seem to be shifting towards the dragonborn ancestry model, where you pick an option from a table that determines the selection of a number of options for a common feature for the species. E.G., damage type for the breath weapon and damage resistance with dragonborn, always-prepared spells with elves and tieflings, etc.
One thing that is nice about this approach is that it’s very easy to homebrew new options. Want a custom quicksilver dragonborn ancestry for your home game? Pick a damage type and it’s good to go. Have a player in your Curse of Strahd game who’s character just died and wants to know if they can play a dusk elf? Just choose a cantrip, a first level spell, and a second level spell that feel on-theme, and Bob’s your uncle. The furry at your table is desperate to play a Tiefling descended from Arcanaloths? Just ask them what cantrip, damage resistance, and two spells they think a fox demon would have, and bada-bing, bada-boom!