I seriously undercharged when I started out meaning I had to work as many hours as possible to make ends meet. When I got confident enough to raise my rate, I was able to scale back my hours and work 3 days on freelance projects and 2 days on bootstrapping. The problem I found was transitioning away from the freelance projects (my bread and butter) and dedicating more time to my app which was putting more of a demand on my time as it grew.
Camino has been open source and developed entirely by a community of volunteers for most of its life. There were extensive instructions on getting involved on the website for many years. There was even a specific push to recruit new people a year ago to make the transition to WebKit so that it could continue to use a modern engine, which is the only way it could have survived once Gecko stopped supporting embedding.
If there were a community of people with the time/interest/skill to develop it further, the project wouldn't have shut down in the first place.