I have an ultrawide as my main monitor and a regular wide screen monitor floating above it on an arm. The main thing I need all that space for is running ttrpg games, honestly. Roll20 or some other vtt open on one side of the ultrawide, then other side has rule book pdfs, enemy stat blocks, notes, etc. The top monitor has discord for chat as well as everyone’s webcams.
But outside of that it’s nice to have a browser or discord visible on one screen while playing a game on the main display, but you could get by without it.