And snap doesn't address the fact that the server components that talk to the snap 'store' software is closed-source and only available from Canonical.
Never claimed it did. Snaps are yet another half baked Canonical tech...
Those of us using immutable distros would love a "flatpack for cli utils". OS-tree layering defeats many of the points of immutability, and pet containers are a bigger pita than they should be. There has to be a better way.