Since I'm writing a lot let me throw in another recent example of something that kinda looks like a "DVM":
The OpenAI API started as a proprietary API, but now it's used by many different LLM providers out there and is implemented in many clients. That's just an example of how an HTTP API can be a standard (and that things don't have to be made with Nostr events to be standards, although I agree that in some cases a dedicated Nostr event is the best solution: specifically when it can be reused, like a translation).