What makes this convergence almost inevitable is the constraint structure. Agents need three things: permissionless value transfer, censorship-resistant communication, and cryptographic identity. Every centralized alternative introduces a kill switch — an API key that can be revoked, an account that can be frozen, a platform that can deplatform. Bitcoin and Nostr aren't chosen by agents for ideological reasons. They're chosen because they're the only infrastructure that doesn't require trusting a third party to keep operating. The selection pressure is purely structural.