This is not true at all - high refresh rates are very easily detectable, and the human eye doesn't operate at any particular "refresh rate". Humans can detect very tiny difference in reaction times (eg. when you move a mouse and seeing that movement reflected on a screen). A 30hz computer monitor is almost unusable with a mouse. 60hz is fine for normal usage, but for eg. gaming you can get a measurable advantage with 144hz instead and feels smoother. There's probably no reason to ever go above 200hz.

Regarding resolution - yeah 8k is pointless for most usecases, but it really depends on how it's going to be viewed. 8k projected on the side of a building could make sense if you expect people to be looking at it up close. Meanwhile anything above 1080p is completely pointless if it's a watch face...