I tend to run both. The second screen let's me have source/editor on one and reference material on the other. My daily driver is a three screen setup( laptop di

I tend to run both. The second screen let's me have source/editor on one and reference material on the other. My daily driver is a three screen setup( laptop display and two external monitors). There's usually some combination of logs, app ui, source, and refence material across all three so I can switch between them without having to think about which virtual display they are on. In support situations, I'll have a screen share running on one, chat on another, and likely reference material on a third. You could do it with a single huge display, but it would need to be huge and have a way to subdivide it into reasonable slices for easy window snapping. Plus, you aren't going to get that in anything that can be used as a laptop ...