It's not defeat, it is the expected outcome. Out of 20 or so of my projects two have been break-out successes and the rest (commercially) complete failures, and I'm very lucky to have two out of those 20, with very small variations in timing it would have been a big fat zero. So don't beat yourself up about it, some people win the lottery and the majority don't. There is absolutely no recipe that will work every time…
I was an engineer at a successful startup. We grew, we went bankrupt, we laid off most the company, the founders kicked in enough to keep us going and we restructured to give the remaining people larger shares. We became profitable and finally sold to another company. My payday was about $70k, which was a nice bonus, I was happy to get it. I moved on to big tech. The company withered away, the company that bought it…
When I've spoken to people about the finance/big tech/startup trade-offs, we've often talked about the upside from startup success (outside of the Google or Instagram case) being around an order of magnitude bigger than that - in the 'pay off your mortgage' ballpark. Is this unrealistic?