I have dual 1080p/60Hz monitors. The bonus to that is everything I play regularly is getting over 60fps, so the screen is flawless and I don't register any dips. On high Hz monitors, if you go from 120ish fps to 60ish fps, you'll see it. But then again I'm using a 7yr old gtx970, which would be somewhat equitable to a rtx2030.
As to which is better, that's going to depend on your game choice. For open world, strategy, slower moving games then 1440p/60Hz is great, very good picture quality. For CSGO, BF series, gta series or other fast action games, then higher refresh is better for a cleaner picture, less ghosting, less stutter, seemless game play. A 1080p/144Hz would be a better choice.
Archaic59 was right about screen size, but only half way. 1080p is 1080p, doesn't matter if it's a 23.6" monitor or a 70" TV, it's identical, exact same pixel count and thats all the gpu sees. The difference is Distance. If the monitor is close, arms length or so, away from your head, then 23.6/24" is maximum size, as 27"+ uses larger pixels to fill up the space difference. So if the monitor is a foot past arm's length, a 27/28" will look the same as a 24" that sits closer. Same as you'll sit 15ft away from a 70" big-screen to get a good, clear, un-pixelated image.