Many free things exist in the world. Not everything is about money. Free services are widely used in decentralized tech. Just look at the Fedivere
The incentives of pay per note (PPN) would build a strong Bitcoin-denominated worldwide economy and incentivize important infrastructure for the future of service on nostr. Relays, media hosting, dvms, etc. If they run on Bitcoin we create the Bitcoin economy we desire. I imagine a future where relay bots compete with each other to offer PPN nostr services so that they can pay VPS hosts in Bitcoin. Uncensorable, unstoppable, and no target for seizure of prosecution.