Yes, makes Debian desktop perfect. Rock solid base system, all desktop apps updated to the latest and greatest without pollution.
Are you trusting Flathub?
Yes BUT… there should be a way to have / manage / install Flatpaks offline like AppImages and/or easy and officially supported ways of archiving the repository into something useful and easy to use.
Too much security already: github.com/flathub/org.keepassxc.KeePassXC/…/29#i…A password manger can’t community with a Browser as it is. This makes both useless and kills one of the best use cases for Flatpak.