It doesn't solve the multiple install methods issue. Fedora for instance already has this via Gnome Software, but provides a drop-down if multiple sources are

It doesn't solve the multiple install methods issue. Fedora for instance already has this via Gnome Software, but provides a drop-down if multiple sources are available for an application, so it's still fragmented. Even if you removed that and had some sort of heirarchy, one app might have a better experience via Flatpak whilst one might be better via RPM. Until developers consolidate it's really not solved, IMO.