A) I think you are successful. B) For the next opportunity, pretend like you are an investor. You are investing your time. I heard one “I thought it would succeed”, I didn’t hear that for all the companies you worked with. I heard what you got out of some of the others. If I were you, my next opportunity would be self-led. Go to events in an industry you are keen on. Scope out the smartest person in the room and tell them why you can help them succeed, independent of whether or not they are hiring. Disclaimer: Easy for me to say what I would do, with no skin in the game.

Build enough to validate that there is a market and you have so much demand you can’t do both jobs. That’s the time to jump.