I mean not all businesses need to thrive. If the thing generates significant profits for a while then the founder can retire and either sell it or just let it die. If it's not a publicly-traded company there's no fiduciary duty to do anything more than that.
If we were riding on momentum I would expect our revenue to be stable/shrinking, not growing (as it is). I agree that in the long term this is true, but when you start as a tiny speck, you can grow for a long time as awareness spreads. For example, we started our in education and are now getting interest from news/media organizations. This is without changing the core functionality at all.