I think everyone agrees that the overall skill level of professional pool as a whole has increased in the modern era. But, the best players of the 60s, 70s, 80s, 90s would be world beaters in any era.
One of the most ridiculous displays of power and skill I ever saw was Earl on the 10 footer against SVB (TAR Match). That table was *hard* and Earl made it look like child's play, in a way I don't think any other player could do. And that's just 2 or 3 years ago, not even in his prime.
Yeah, when the Earl of ole shows up watch out. As long as he can keep his demons at bay I would pit him against anyone in any era. Maybe he wins and maybe he looses but he would always be a threat. When he played the Mezz in Tahoe in the 80's he was a GOD.