To me, it feels similar to what’s happening on the server side. Server Side, most application handling got replaced with containers, because the dependency management becomes untenable if you’re pushing around just a couple of in-house applications. Here you use the distribution to offer a stable platform (container engine, monitoring, storage and such) and then run container on top.

And I think the desktop is on a similar journey for similar reasons, at least for faster moving or more complex applications.

Sandboxing your applications is the way to go but there’s no way I would let Snap or even Flatpak in their current form replace apt/pacman on my distros. I would be much happier to see pacman/apt/etc. introduce their own containers

Yes, I think so. It’s a lot easier to maintain your distro if the maintainers of the project handle everything regarding application packaging.

There is a snap version of gui ubuntu coming out where the entire desktop is snap

I hope so. The fact that packaging and in essence software distribution has become a distro maintainer’s task is really weird and shouldn’t be.