MyNameIsRichard

My experience of anything Ubuntu based is that it is buggy as hell. I have no knowledge of Fedora.

https://gitlab.gnome.org/groups/GNOME/-/issues

KDE doesn't seem to give you an overall view

What part of

All software beyond a moderate complexity has bugs.

didn't you understand?

Doesn't work on my machine is an opinion not an argument. Different people have different expectations and experiences.

Not an excuse tbh.

The thing to do is participate in the beta programs and report any bugs you find, as you're having so much instability you would be an ideal participant whereas me with my smooth running wouldn't.

It really isn't, at least in my experience. And I have an Nvidia card!

All software beyond a moderate complexity has bugs.

KDE Plasma is wonderfully stable if you mean reliable, if you mean unchanging then yeah, it has quite a few changes.

Again it depends on what those repositories do.

EndeavourOS (Arch based) adds a repository which appears to be for their utilities, otherwise they use the Arch repositories. You could probably continue using it with minimal disruption although the utilities would be unmaintained.

Manjaro (also Arch based) uses its own mirrors of the Arch repositories and adds some of its own. If it vanished, it would quickly become out of date and full of security holes. A new install would be necessary.

In either case, I'd do a clean install of Arch because why give yourself the headache.

It may just be a pre-configured Debian in which case there will be nothing to convert or it may have several additional repositories in which case it will be easier to install the new one.

No one ever mentions Crux Linux

The only time I come close to that number of updates (300 - 350) is when KDE Applications and KDE is updated at the same time. I update twice a week.

I should have been clearer.