I don't use Ubuntu but I threw it on a laptop to give to my dad.
He's a very basic tech user he basically needed a web browser and somewhere to backup/view his photos off his phone, And even he ran into issue with snaps!
I tried to switch everything over to flatpak but the OS just kept pushing back trying to reinstall SnapD until I ran some script off Github, It's the exact "I know better than you" bullshit that pushed me away from Windows.
If you really want everything to go on flatpak why not just use Debian + GNOME? No bullshit and you'll be able to have flathub inside the GNOME software "store".