I love it when I've read these articles of the type saying: the human eye cannot distinguish resolutions higher than X, or more colors than Y.

Uh, yes it can. :-) I absolutely grasp the theoretical principles behind why you shouldn't, in theory, be able to tell the difference between an HD and a UHD movie when sitting more than about 4 feet from your TV. But I can--and everyone I know can. Same thing between a 200 DPI screen, and a 300 DPI screen. Or photos take at 12MP, and those take at 20MP. The difference is not hard to distinguish, particularly if you work in front of screens all day as I have for over 25 years.

Maybe everyone doesn't CARE enough about higher resolution to spend the money for it, and maybe it doesn't make a huge difference in the end--that I'll buy. That's a value decision. But people can tell the difference between 200 and 300 DPI, HD and UHD, and non-HDR and HDR pictures. I love the crispness on the 323 PPI screen of my Nexus 7, for instance, and can tell a clear difference on text clarity between that and cheaper Samsung and Amazon tablets at Best Buy I've seen in the ~200 PPI range.