I want to add another anecdote: I built an app for creating certificates[1]. It was originally a case study for a book I'm writing, so I didn't think much of "target users". But then I decided to make it a real/standalone product. I was struggling to find real users.
Then, just by sheer coincidence, a friend shared his struggle with existing ticket sales platforms. I thought, "Hey, with what I've built so far, it's just like adding another 10% of work" (It wasn't). So I "expanded" the app to become a white-label ticket sales platform[2]. People started using it, and they also use the certificate generation feature ("Your app can create certs for attending events? Sweet!").
I don't know how to distill this into advice, but you get the idea. It's like a South Park meme: Step #1: Listen to users, Step #2: ???, Step #3: Profit!