I built a successful one, and sure - it gave me a decent income for 10 years after the initial 1 year of working on it. But altogether it was around €0.5M over it's lifetime, and it took me 5-10 years of unsuccessful projects to finally do one that succeeds.

It is a common experience as well. That's where the saying comes from that "it takes 10 years for an overnight success".

Also, the difference is in payout. When you work for someone, you get paid monthly. When you work on your own thing, you get literal 10 years of people making fun of you and saying "why don't you find a real job", and then - if you succeed - you get the same people complaining that you drink pina coladas.

I've been to the bay area, and it's the most work-intense environment I've ever seen. There is no easy money there.