Original Pinephone is good enough for smartphone apps. It can run a typical smartphone UI smoothly on a single core fully throttled to 648 MHz with a lot of room to spare, probably much better and more responsively than your typical similar class bloated Android phone. Also have it sitting on my table, doing just that. :D

https://xff.cz/dl/tmp/photo-20260806-013112002.mkv (I guess I try hard enough, perfectly servicable with a single core at 648 MHz, barely scratching it at 10-20% CPU time used)

It would be a bit ridiculous if it was not, given what UIs/games people run on 50MHz 486 if like 40-80x faster phone could not move some pixels around smoothly at 60fps.

Well, even the Neo Freerunner worked smoothly if you tried hard enough :)