Re: Irrational fear of upgrades?
"...it's not so much the ease or otherwise of upgrading. It's that I have a stable system I'm using to do useful work and then a major system upgrade breaks something...."
In all the iterations of Fedora I've used (as one of several distros in my various desktops), Fedora either makes everything work or nothing works when you update it. I've never had an issue where I got to the login screen and then something after that point didn't function properly, it's more of a thermonuclear situation where all of the sudden it fails to boot and I need to fiddle for a bit. It keeps a copy of the old version anyways so it's never a real hassle.
As far as my main system (PopOS!/Ubunutu) goes, I find that as long as you stay on the LTS releases that basically never happens.