The appeal of Flatpak is not that I prefer it to my distro package manager.
The appeal is for the application author who finds the fragmentation in Linux a problem. It is a way for them to target “Linux” and not individual distros. It is a way for app authors to control the distribution and the support surface in a way that turning over control to package managers does not allow.
Which means the appeal for me is just that I can get apps as Flatpak that I cannot find in my distro repo.
On Arch, I hardly ever use Flatpak. On other distros, I use them more. I do use the pgAdmin Flatpak everywhere though because all the distro versions I have tried are garbage.
Niri rocks