What looks like redundancy is actually the only rational strategy in a hits-driven business. YC knows that most investments will fail or return modest multiples. They're not trying to avoid failure—they're trying to ensure they're in the room when exponential success happens.
You don't need five wins. You need one Stripe, one Airbnb, one DoorDash. That single outlier will generate returns that make every loss, every write-off, every failed bet completely irrelevant.

That's why YC bets on similar ideas, back competing startups, and invest in spaces that look crowded. They're not hoping lightning strikes. They're buying enough lottery tickets to guarantee they're holding the winning number.