All securities are held by someone and the total return of the market is the total return of all those securities. For someone to outperform the market he has to hold a mix of securities that outperforms and whoever holds the opposite mix underperforms. Sock market returns are very much zero sum.

>the other side of well managed hedge funds are usually poorly managed pension funds/hedge funds

How do you pick ones from the others?

>index fund ETFs that blindly buy a bunch of stocks without looking over their financial statements

That's the point of those ETFs, replicate the index exactly. If they're replicating the market average then they're doing exactly their jobs.