As a user of a crt pc monitor and a 240hz oled, the motion clarity of the oled is pretty darn close now. I’d bet 480hz is the point where the smoothness of modern panels finally catches up to the crts.
Of course the question is how to leverage those monitors. Either games have to render 480 frames per second (which is impossible on average hardware in most cases other than Subpixel Snake), or the monitor just displays 7 black frames after every rendered frame, which would cut down the games to 60 (rendered) frames per second. But the latter would of course greatly reduce the maximum screen brightness to 1/8, possibly below CRT level, because OLEDs aren't very bright in the first place.