4 Years of Service
Mostly, I don't want to do a lot of time moving around between things. When I want to copy one thing into another thing, drag drop. I don't want to have to stop playing BG3 to preview email as it comes in. Stuff like that. I have friends that think it's silly, until they hop on to work on something and then they never want to mess with a single screen again.
I like dual screen just for this very reason. But I am only at my second monitor during the day, during "Work Hours" when I log off from work, I move down to the lounge. Then my "Second Monitor" is a TV with whatever I'm watching on haha.