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.
Been doing it for years as a sysadmin. Great for documentation and multiple terminal windows. Interrupting programs (email, messengers) on the small screen so they are easy to review but out of direct line of sight.
Small screen makes it easy to screen share with others. They can seen the whole thing at a reasonable size.
3 monitors here, also as a Sysadmin. One for a browser window and tickets, one for side apps like password managers/comms/music/document handling/whatever, and the last is for all the remote desktop-ing I do into various machines throughout the environment.