I think it's maybe to add a security layer in the case of crashes but I don't really know. Simple apps were good since they had the same UI and the transation felt good.
Dialer apps are a mess, waiting for Fossify also here
Archlinux has the best wiki and community for every type of issue.
Steam Decks?
Oh, I'm sure we're all great parents here. I applaud you for admitting a mistake and having the humility to ask for advice, both excellent parenting skills in my opinion.
I believe the answer is always culture. Once better videogames are discovered it's likely that they will hardly go back to the bad ones (so that the problem of prohibitionism - which is only a temporary solution - can be solved).
I've installed Flowit, Xeonjia, Parlera and Pirate Solitaire.
Divide et impera
I also was an user but Aves Libre is a very good replace if you don't mind the video editing aspect. But yeah, that app also probably deserve a good fork.
There're good alternatives for every app, the only real lost are contacts and dialer, imo.
SimpleX Chat
I'm actually using Ardour as my daily daw, very powerfull (check my profile if interested in libre music). Consider I made electronic music for many years with proprietary software.