I was a #1-ranked stock analyst. And I indeed outperformed the market on my and my parents' accounts. I also know a small hedge fund manager who I believe could consistently outperform the market. But in each case the strategy was to know a small portfolio of underfollowed stocks very very well. It's not something that could scale. He eventually just dumped his clients and managed his own money. I stopped investing in anything except index funds after I stopped being a stock analyst.

I.e., I agree with Buffett's general premise, and have since the 1980s.