this is subjective and not objective
the best thing for you to do to get this answer is to look at a 27in 1440p display next to a 27in 1080p display, i can sit here and tell you how much i love my 1080p 27in monitor and how i want to get a 34in 1080p ultrawide but all of that is my opinion, we are all different people and we see things differently, to one person 1080p on a 27in display looks terrible but 1440p looks great and to another person they can think 1440p on a 27in looks terrible and 4k looks good
best thing to do is compare them for yourself and see what you like more