Without having deeply investigated myself I read the snap server is proprietary, nobody can run another instance. So nothing I want spend time on to even understand. (The client side gets some complaints, too. But without understanding the system I don't want to form an opinion, I uninstall it from the Ubuntu systems I still have.)
With flatpak you also don't have to engage in this wierd /snap trickery.
We're getting there.
Edit: CoreOS -> Silverblue. Thanks to LeoPanthera.
It is definitely usable and even good, but there is edge cases that ere not figured out, I feel. It needs more blog Posts, Docs, Tutorials ...
You can use either one you want but keep the same base OS, as far as I can tell openSUSE is the only immutable distro that lets you do that, which I think is pretty cool.