Your description of a VC's value is describing them as an index fund of startups, and I suppose you could say YC has moved in that direction. But most VCs are

Your description of a VC's value is describing them as an index fund of startups, and I suppose you could say YC has moved in that direction. But most VCs are paid to make bets on which companies are most likely to succeed. I never said they're supposed to know with certainty. That's a silly straw man that no one who understands basic finance would suggest. But they spend much of their time supposedly screening deals to find good ones, and there is a preponderance of evidence that they're worse at it than a dumb index fund. There have even been experiments to automate picking deals, and even a fairly naive algorithm is better than most VCs. Only people on the VC side of the table think they have any added value other than lucking into being trusted to invest other people's money.