If you only play competitive fps titles then 240Hz would be pretty beneficial. I am a rainbow six siege player and I have tried 240Hz monitors before which has a noticeably smoother experience.
But I'm using a 1440p 144Hz display which balances gaming and work stuff, as 1080p for me is very grainy and I found 1440p 27inch to be the bare minimum for pixel density. Although this is just my experience, some people may not be that sensitive on pixel density.