Thanks, I was looking at getting a Monitor around the 28inch mark. I will be sitting a lot closer to it since ill be moving my PC and using a PC desk. The bright side is if I go 1440p, that will free up some GPU power and can focus more on framerate since monitors have such better hertz compared to TVs.
28" @1440P is 104.9 Pixels Per Inch.
Contrast that with your 55" Television...
55" @2160P is 80.1 Pixels Per Inch.
A 21" @ 1080P monitor is also 104.9 Pixels Per Inch...
So in terms of pixel density, the 1440P monitor will beat the 55" television... The big variable is how far away you sit from said displays.
But 1440P is a good balance in my opinion, you don't need as much hardware grunt, so you can drive up the visual settings instead.