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.
I used to swear by two monitors, but switched to a single ultrawide and it's so much nicer. No bevels in the middle and therefore freedom to set up windows in whatever configuration you like. Good tiling window manager is a must though.
If you're on windows, display fusion was great for this. Since I switched to Linux, KDE just natively does everything I needed display fusion to do. Changed some key binds to match what I was already used to and was off to the races.