Groups like ELP, Yes, Genesis, et al, probably kicked off the entire Punk movement with their extreme virtuosity. It gets to the point where kids just look at that and realize, ‘No way”, and you get a reversion to 3 chord rock and roll,
That being said, these guys were on a whole other level from everybody else, and I mean Everybody Else, regardless of whether you like the music or not. I don’t know if there is now, or ever has been, anyone operating on this level, especially live unless you count Beethoven or Mozart. Stunning that they could reproduce something like this live 20 Years after the fact.