Countless blind tests have shown a noticeable difference up to refresh rates over 100hz (and potentially greater). This is the first of many examples that I found: https://techreport.com/news/25051/blind-test-suggests-gamers...

"The human eye can't tell the difference past 30 FPS" was literally just a thought-killing cliche repeated by console gamers getting into internet slapfights with PC gamers.

You can see the difference for yourself here on any 60hz monitor: http://www.30vs60fps.com/