It depends on the use case.

I frequently use two terminals side-by side; for this type of work, 1920p are enough [for me]. They're enough also for diffing source code, as long as the lines are not excessively long (around 100 chars fit on each side; comparing 2 lines long statements is acceptable)..

I think a use case where a single (1080p) screen is significantly inconvenient is for windows with a fixed shape, for example, debugging a videogame.