One reason I find it hard to grasp is that when I work on Windows, it's almost always through RDP or VNC. There is never any question of a terminal (or a process launched from it) staying open between login sessions, because it never depended on any particular connection to begin with. It's just there, on the desktop, which might stay up for months before I need to connect to it again. Any terminals or other processes I launch on that system will be there until I close them intentionally, or until Microsoft decides to reboot the system without my permission.
So when I dip my toes into the Linux world, the first thing I do (or rather ask an LLM harness to do, being much less familiar with Linux than I am with Windows) is set up an RDP host. That way I can follow the same basic workflow on both OSes. I don't need to do anything special with terminal windows.
I guess if I were running truly headless systems that don't even have a VGA frame buffer, I'd be more interested in multiplexing. But so far I haven't had to do that, and would probably resist it because a persistent desktop strikes me as better in general than letting applications including terminals worry about their own lifetimes.