Earlier quoted context omitted.
On top of my mind, I think of: Brew upgrade usually breaks stuff if it hasn't been updated in a couple of months, which is not the case for other package managers. Forced update on any command is really bad behavior.
Per gp, I haven't used Pacman in a long time, but when Arch was really popular I'd have a virtual machine, ignore it for a few months, then updates usually failed or rendered the machine inoperable. The Arch wiki was so good that it inevitably included the exact problem and resolution already, but since I didn't have any important running systems I also might as well have reinstalled the whole thing. In which case I'…
NixOS has a similar strategy.