Started this as an open source project with the goal of first creating an ecosystem. So far, I have been getting good reviews from people who are using it as a search solution.
Eventually, there will be certain premium features that maybe only 10% of people will really want, and I will charge for that. Playing the long game here.
Good question, and something that's always on the minds of open core companies these days. In my case, I don't mind, and in fact would welcome it! It would solve my no.1 pain point: discoverability.
I'm not planning to build a billion dollar startup out of Typesense, so I don't face the same problems that Mongo and ES do. I also don't plan to offer a hosted version of Typesense. If somebody else fills that void, I will happy to let them do that. For an infrastructure product, there will always be people who want to run it in-house -- there is enough $$$ to be made in that space.