I’ve been using it as my main for months. Even as an Alpha, it’s very stable. That being said, it’s missing quite a few features that a lot of people would consider a requirement. So “ready” will heavily depend on your requirements

Definitely not just for handhelds. Check out Universal Blue images which are built ontop of Fedora Atomic (the immutable variant). Bazzite is an awesome gaming distro that’s rock solid. Bluefin is awesome for Devs and more technical people. But even for non-devs it’s awesome since the images are purpose build with and without all the devs tools. You pick your preferred DE (KDE or GNOME), and your graphics drivers.

Almost everything is setup for you that you would have to do mannually compared to Fedora Atomic, and additional quality of life tweaks are included as well.

Been running, Bazzite on my gaming rig for months now and it’s been great. Running the Cosmic/Gnome UBlue image on my framework laptop for months and its also been amazing.

This should add the flathub remote to the system and then install all the existing user packages into the system level. Then removes all the user level packages.

flatpak --system remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
flatpak --system install $(flatpak list --columns=application)
flatpak --user remove $(flatpak list --columns=application)

Personally I would just pick all the ones you’d like to be global (system level) and leave the rest at the user level.

Check out GrapheneOS. They sandbox google play services so you have a lot more control over what is sent to google. Might be a good middle ground.