I have been working on an OS project for years now, on and off, taking it back up for the last few months and giving it a good boost lately with AI. It has a super niche user base in quantitative finance.

I really enjoy working on it, and although I get contacted every now and then by people who are using it or are interested in using it, and those are really interesting users, I always think I am wasting my time. It has been 8 years now since I started.

I guess my questions are: is it worth it? And I know this question has two clear paths, the personal and the practical one, but I would like to hear from both. How can I know when to stop? If my audience is maybe in the order of two thousand potential users worldwide, how do I validate the idea? I have posted on Reddit and HN multiple times, tried LinkedIn, and that leads me to a handful of super interesting contacts, but I don't know if it is enough to keep going.