We'll have to wait and see, because Nostr is grounded in physical reality and capitalism. What's monetized is what will survive. The clients and services that can pay their server and development costs will survive. The businesses which sell enough products by advertising on Nostr will survive. The creators that get enough zaps will survive.
I agree, economic activity is what will make Nostr thrive, because it's a necessary condition for its survival in the first place. By being a free platform and a conduit for free money, I think Nostr has the best chance possible to be where everyone ends up.