>you should upgrade often
But you litereally started by saying that upgrading any given Friday is not quranteed to leave you with working OS
To give a practical example. In 2013 Arch Linux merged all binaries into /usr/bin. This architectural improvement was obviously a major change, and the way Arch is designed as a rolling distro meant that you couldn't leave users behind on the old way of doing things. After the change, everyone needed to be using the merged /usr/bin.
This is a designed lack of backwards compatibility that means you're guaranteed to be using the latest system architecture at all times, reducing the maintenance burden for the maintainers and making sure everything just works most of the time. But it also means that you have to be willing to do system maintenance to get your local system in line with what the Arch devs use. In the case of the /usr/bin merge, manual steps to perform the upgrade were required. [1] They weren't hard, but Arch requires this kind of oversight as part of its design.
If you're not willing to perform that kind of maintenance, then Do Not Use Arch! It's designed for people who are - although in practice this kind of intervention is required only about once a year.
[1]https://archlinux.org/news/binaries-move-to-usrbin-requiring...
Not "if it's ok to update", but "whether there's manual intervention required". See https://wiki.archlinux.org/title/General_recommendations#Pac.... Not reading that before upgrade seems to be the main reason for post-upgrade failures.
> But you litereally started by saying that upgrading any given Friday
The point was that you should rather upgrade "every Friday" than "any given Friday".
Says who? That's pretty much not what Arch tries to guarantee at all. You're at the very least supposed to read the announcements and you should upgrade often, as otherwise the end result is undefined. Some distros like Debian support partial updates, Arch very explicitly does not.
If you use Arch the way it's intended to be used, you're not going to have to spend a day every now and then to fix your OS, but if you don't, you will. I use it as my work system for years and every time I broke it was my own fault.
And if you don't want to use it the way it's intended, then just use another OS that better matches your expectations. I don't use Arch on my server after all.