Haven't read the entire thread, so hopefully I'm not repeating points already made.
For me, the "floating ASI's" from Tasha's isn't really about those ability bonuses. It's about decoupling ability scores from race/culture, which is important to me. But with 5E's current balance, you can't just rip out those ability bonuses, so they become "floating", you can put them wherever you want.
Ideally, in a future edition of D&D, there would be no racial/cultural ability bonuses, and no "floating ASI" bonuses either, because they wouldn't be necessary.
Either way, it helps the game move past some uncomfortable assumptions about race, culture, and inherent ability . . . and also (as a bonus) helps us move past stereotypical character builds.
When initially determining ability scores, and using the classic random dice rolls to do so . . . adding some extra points to be distributed any way you like I think helps give the player a stronger sense of control and ownership over the creation of their character. Roll 3d6 six times, assign the results to your scores, then add 3 more ability points as you want to help build your character. Huh, perhaps I just argued myself back into wanting the floating bonuses kept in the eventual next edition . . . .