Nowadays, a lot of Linux distributions like Ubuntu, for example, will do an update and then tell you that you should reboot, even if a reboot isn't strictly necessary. You can still ignore and postpone, but I think most users will see this as very similar to Windows.

Windows machines frequently do updates without a reboot nowadays and you can usually postpone an update to a more convenient time.

The problem is that when an update that requires a restart is waiting, it changes the standard restart button into one that does an update and restart. You can often fall into muscle memory and accidentally trigger an update.

When combined with the fact that you quite often get problems that go away with a reboot you can easily get yourself into OP’s position where they’re waiting for an update to finish at a really inconvenient time.

Not even doing an A/B partition kexec update scheme with VM live migration for all critical services??

Oh wait I'm a stereotype

remember because my Linux machines take at most 5 minutes to update

I keep kicking myself because I'm using fedora Kinoite on my slowest machine. It's going to get arch eventually, but for now it's just annoying whenever I go to use it for a few minutes until it finishes the update.