If you want to make a gambling analogy, I’d say making money off your equity grant at an early stage company is more like playing Roulette (with a better payout) than buying a lottery ticket. Sure, it’s uncommon to win (in this case hit your number) but it happens with decent frequency.
Perhaps it was my gambling addicted stepfather who died broke that keeps from seeing the appeal.
You’re not risking your life savings by joining a venture backed startup as an employee. In the worst case you write off a few thousand dollars you spent exercising some options while making a market rate salary (because you negotiated).
... because no startup is willing to pay competitive total comp fully in salary. Bigcos mostly aren't either, FWIW, although RSUs of a public company have a lot more liquidity and lower volatility than startup options.