it seems to me that while 4K may be standard in other fields (e.g. media, movies), in gaming, many prefer to trade resolution for higher FPS [1]. The middle ground (1440p) seem to be quite popular lately among 'normal' gamers, but I think that in competitive gaming many still prefer to stay on 1080p and achieve very high FPS. Competitive gamers also do a lot of other 'strange' things, for example I saw people who select a 4:3 aspect ratio and stretch it over 16:9 instead of running 16:9 natively [2]
[1] https://www.digitaltrends.com/computing/steam-july-survey-re...
[2] https://medium.com/@lurppis/the-16-9-vs-4-3-aspect-ratio-arg...