I don’t have the answer to how we’d scale globally to many millions of active users, and not sure if anyone does yet. Everything is so early that there are so many experiments to run to see what works and what doesn’t. I don’t think anyone can draw any definitive conclusions on funding methods yet. I think partially and perhaps ironically is that you need scale to figure out how to stay funded at scale. There are far too few users to draw any serious funds from right now.
Regarding echo chambers, I don’t think any social network is immune to them. Even nostr. We have somewhat of a bitcoin echo chamber right now for obvious reasons. A lot of that goes away simply with more users. Nostr does have a strength in that it’s censorship-resistant and more tolerant of differing opinions. We are building tools to curate our own experiences with options to form our own bubbles, or not - totally up to the individual.