Not everything needs a business model - Non-commercial FOSS is also a viable option. I generally think companies are preferable, because they're self sustaining. But sometimes you can't combine the software with a business model. Mutiny is an excellent example of being "high risk / low reward" (I.E risk going to jail for cents on the dollar of micropayments).

Nostr is doing just fine with almost only being FOSS - We already know a lot of people will just develop clients for themselves and run relays pro bono. I have no worries there.