In fact I’d say they are perfect for distributions to be more stable. E.g. : my issue with Debian have always been that you couldn’t (easily, I know backports existed) have stable system AND fresh software. With Flatpack, you can.

Now I can run my latest user softwares on a stable distribution. That’s pretty cool.

There are still issues of UX. Especially when the app you are using doesn’t have enough permissions to do the job, you have no information about it and when you guess it by yourself, changing this is hard.

I’d expect that Flatpack should allow apps to specifically ask for permissions in real time or when they try to access external resources like in macOS : just expose the APIs but make them wait for user approval.

> Now I can run my latest user softwares on a stable distribution. That’s pretty cool.

I'm at a bit of a loss. Isn't the entire point of a stable distribution _not_ having cutting edge userspace? It's an inherently double edged sword.

If you just wanted to mix and match you were always able to run (for example) a debian testing chroot under debian stable. Something like Nix is the more extreme version of that. The point of something like Flatpak then is either sandboxing or the distribution model (ie getting software from the original author).