The best I have to share with you is a mediocre "sort of successful but only if you don't count my labor cost" project.
I've been working part-time but consistently on Alchemist Camp for three years now and it still earns less than 1/3 per hour of what I could previously contract for as a dev.
I think the biggest reason is because I optimized for multiple constraints. I didn't choose the market or the product purely for the immediate economic opportunity. I was also optimizing for increasing my skill with the tech stack I saw (and still see) as most advantageous for a startup founder to have skill with. On top of that, I was optimizing for a third constraint of something that I could do with a maximum of two hours a day of keyboard time.
I've been working part-time but consistently on Alchemist Camp for three years now and it still earns less than 1/3 per hour of what I could previously contract for as a dev.
I think the biggest reason is because I optimized for multiple constraints. I didn't choose the market or the product purely for the immediate economic opportunity. I was also optimizing for increasing my skill with the tech stack I saw (and still see) as most advantageous for a startup founder to have skill with. On top of that, I was optimizing for a third constraint of something that I could do with a maximum of two hours a day of keyboard time.
If you're curious about the project, I just shared a full break-down today: https://questinglog.com/2020-year-in-review/