Good luck! I genuinely hope you succeed. Unfortunately I would be lost without things like Android Pay, Sky Q, Ring Doorbell and my other smarthome apps (quite a lot of these) so it's not an option for me.All my apps have a Linux equivalent or already have been compiled for Linux, web browser, media player, telegram, file explorer, ftp server etc. so I won't have any issues in that respect.
It's not simply about FRP I want to move away from Android because what was once a really open platform is becoming more closed and controlling of your device that it becomes a pia when trying to do some basic things.