Interesting idea. How's it going so far? Do you have any customers?
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.
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.