I think it's good that the KDE project is working on fully featured operating system. I'm less excited about the decision to use Arch. Nothing against Arch in general but I just tend to prefer other distro's.

I'm less concerned with snap/flatpaks/etc. to be honest. They aren't my favorite but I can see the industry and other groups moving to them. They make tools approachable for a general audience and I think that is mostly a good thing. The Linux community has been mostly shielded from bad actors and viruses. Sure we've had a few but nothing at the scale of the Windows community. Newer tools change that for sure, but I don't think they are necessarily a five-alarm fire.

With all the new users, the Windows 10 stuff, etc. it makes sense that there are going to be brand new solutions. It's cool the community is evolving.

I agree with you. However with a immutable distro the base is "not that important" for the user as they don't really interact with it anyway. I can see why KDE chose Arch. Bleeding-edge packages, synergies with Valve and Steam OS and just generally Arch having wind in it's sails atm.