I got 'stuck' at a similar place during the recession around '05. One of their projects was just demo-ware we were selling as finished product. When I wasn't on the project it wasn't so much my problem, but as time went on they consolidated all their work on that one, in part to improve their financial story for investors. So then I'm working on a slow trainwreck that I didn't get to set strategic direction on when the project was young and flexible. So many antipatterns repeated throughout that code. I learned to hate/fear caching on that project (ex: you can't cache a table scan, unless the entire table fits into memory, and then it's not a cache).
When we got bought the founders complained about how it wasn't enough to retire on. Aww, poor babies. We were too early (Apple introduced a similar product 6+ years after we started ours), so the payoff was only enough for them to live comfortably for the rest of their lives. Except they immediately got condos downtown with unobstructed water views so I doubt that lasted very long.
I think you had the same problem we did. Potential investors take competition in a space as validation. Legitimate competition just solidifies that validation. The moment you folded, the screws got tightened on the other company. Either they didn't get any offers at all, or with terms that were terrible. Founders don't want to be treated the same way they treat their employees.
(This thing where companies get bought out and discontinue their flagship product is, in my mind, a failure mode. That's not success if you make things for a living. Somebody, not us, got rich, while we have a project on our resume that was a failure by our standards, but makes us more attractive to the next guy who wants to pump and dump a company. An attractive little cog for their big wheel. And maybe, just maybe, enough from shares or bonuses to get a loan on a new car)