I assume you are looking for motivation. This thread might provide some https://news.ycombinator.com/item?id=11924009.

There are many examples of successful single-person startups (forgetting a recent example of a person who ran SaaS product single-handedly for over 4 years and then expanded). However, you can only bootstrap like that. To grow bigger, eventually will have to hire people - which means money, which means either VC or customer - which means tonnes of work in building products/building relationship/shipping product etc. I guess, if startup success rate was 1% then solo-founder startup success rate must be 0.01%.