To those with 2+ monitors on your machine: What's your use case, and how much does it actually boost your productivity?
I'm mainly curious about software developers here, or anyone else whose computer is somewhat central to their life, be it professional or hobbyist.
I only have two monitors—one directly in front of me, and another to the right of it, angled toward me. For web development, I keep my editor on the main screen, and anything auxiliary (be that a dev build, a video, StackOverflow, etc.) on the side screen.
I wouldn't mind a third monitor, and if I had one, I'd definitely use it for log/output, since currently it's a floating window that I shuffle around however necessary. It could be smaller than the other two, and I might even turn it vertical so I could split the screen between output and a terminal, configuring a AutoHotKey script to focus the terminal.
For work, it's usually IDE on the right (my larger screen) and a live build of the thing I'm working with on the left (a laptop screen). Though it varies a lot throughout the day. Primary screen gets the app that needs most scrutiny, small screen gets auxilliary things like passive communication apps or reference materials.
For home use, where I have two monitors of equal size, it's usually Discord on one screen and a web browser on the other. Comms on the left and active task on the right.
I don't see a use case in my workflow for a third screen, especially not one that is a weird size or is in portrait orientation. But if one was simply bestowed upon me, I'm sure I'd find something to do with it sooner or later. There was a time where I though two monitors was overrated, I'm sure I can adapt my opinion again for 3+.