When the RPM felt out of time, I switched from SuSe Linux to Kubuntu. Now I use a ubuntu based distro (Bodhi). This flatpak stuff may make me leave ubuntu.
Ubuntu uses Snaps by default. Flatpaks are an option in Ubuntu only if you install the application.
My current version uses mainly DEB. Due to some personal issues I am not up to date with my OS. I install 99% of my software with apt and deb packages. I don't like Snaps and Flatpaks.
Yes, I have to update soon but I will do this when I buy a new Dell XPS