Just set up a vertical monitor.... what now?

A lot of people seem to have a second monitor set up vertically, and so with my new one coming in the next hour, ive done the same with my current. Its all working... But what do people actually use it for? Whats the benefit compared to having it horizontal? More space on desk? Not a streamer so I wouldnt need it for twitch chat or anything.

Just looking for ideas of good things to use it with!