I am currently using Linux Mint (after a long stint of using MX Linux) after learning it handles Nvidia graphics cards flawlessly, which I am grateful for. Whatever grief I have given Ubuntu in the past, I take it back because when they make something work, it is solid.
Anyways, like most distros these days, Flatpaks show up alongside native packages in the package manager / app store. I used to have a bias towards getting the natively packed version, but these days, I am choosing Flatpaks, precisely because I know they will be the latest version.
This includes Blender, Cura, Prusaslicer, and just now QBittorrent. I know this is probably dumb, but I choose the version based on which has the nicer icon.
I’m sure it does to some degree, though I don’t know if it’s enough to matter on modern computers, and isn’t that what flatpak does, too? (duplicating dependencies)
In any event, if you don’t need an application from a specific distro there’s no reason to create that container. The non-ubuntu ones get created when they’re needed. (And I think the next version of VanillaOS will be debian-based, not ubuntu; in case that matters.)