what?2080 deffo unless you can stretch to ti then even more frames imagine that.
You will see more FPS yes, but the difference won't be as big as if you were at a higher resolution, what someone means by overkill is that it's likely to get such high FPS on even the most demanding games or use such high settings that it doesn't deliver a perceivable benefit in current titles. Like you say, sometimes it might be a 20FPS difference, which could be a big deal if that's 40fps vs 60fps but you're much less likely to notice if it's say 100FPS vs 120FPS.