When I got a 1920x1200 display in circa 2004 that was pretty beast but I could still see pixels, I knew it could be better in theory even if it was already so much better than what else was on the market.
However when 4K IPS and especially the latest generation of 4K OLEDs came along I realised at my viewing distances (and my degrading eyesight) I'm never going to see another pixel again.
So for me I don't see what 8K is going to do for me. OLED with it's perfect blacks and awesome peak brightness and fast refresh times haven't left me wishing for much other than a GPU that can keep up.