Laser printer and printing all books and documents. About 300 pages/week.
8x4k 27" screens in portrait mode plus TV. I connected laptop and two desktops with Barrier, so all share single mouse, keyboard and clipboard.
I found it better to work on multiple machines simultaneously. Background tasks do not slow it down. And connecting 9 displays to single machine is tricky. It is cheap junk, but looks like power plant control center. And productivity gain is there.