Yes, all of this is definitely true and I'm not actually complaining about it, I have used arch on all my machines for 7 or 8 years and don't plan to change that anytime soon, but these problems are actually unique to using arch and other rolling distros. Ubuntu, Fedora, etc have coordinated releases with some level of testing that things are compatible with each other. On arch, these are problems one must deal with though. I don't mind dealing with it, I live for Linux stuff, but the point is that it does happen to real users and it's not for everyone.

> Partial upgrades are explicitly unsupported by the distro. Pacman allows you to do this, but you're on your own.

Definitely correct, the issue is when you're trying to install a package to get something done, and suddenly your faced with the proposition of either upgrading your whole system while trying to get work done or attempting to upgrade just the required libraries. The latter often carries less risk, but occasionally is very problematic.

> And this is why as an Arch user you will be nudged by experience to use software that gives a crap about quality.

The issue is that this is true of so many very major pieces of linux software. Upstream vendors don't necessarily test their stuff in a ton of contexts, plenty of bugs occur in the kernel/xorg/wayland/gnome/glibc/python/etc. All of these are very mainstream projects that are difficult to avoid.