I have broken and repaired many distros in the past and most package managers were able to handle it.

This is why I always keep the last 3 installed package versions around.

In Arch based distros you have to install downgrade. Idk why it doesn't come with the base pacman tools, as it can seriously save your ass.

The most resilient package manager I found to be dnf. I once messed up an upgrade from Fedora 20 to 21 or something and many packages were 20, some were 21 and some were rawhide. Boy did I think I needed to fix this manually. I fixed the misconfiguration, made internet available in a root shell and dnf magically repaired every dependency hell I found myself in.

Fedora is now my work desktop and Arch with snapper runs on my personal devices.

Immutable distros or things like NixOS seem fine if idiots need to use them. However, I'm not an idiot and usually don't give idiots root rights.

If you want your system simply to work and never customise it beyond what the maintainers thought out for you, NixOS and Silverblue etc. might be cool. But for me there always was a point where I had to do hours of work thinking "good Lord Linus the Creator, this would be so much easier with a regular distro".

Went so far to ragequit NixOS three times now and everyone who uses it nowadays gets the same look as these weaboo Arch supremacists way back when. Maybe NixOS is good in 10 years but at the current rate, I'd just burn the project honestly. So wasteful, both for the environment and man hours.