I assume the target audience for the question is developers. That will generate many responses along the lines of ”just use a CLI”.

The current, main driver I see for MCP servers are non-technical people who want to securely connect data sources to their AI application.

Hosted by Apple or not, but isn’t the biggest feature of iOS 27 LLM integration?

The biggest feature is stability, but Apple Intelligence has an excellent toolkit and API.

You mention RSS, but Substack is about paid subscribers, is it not? What do you think converts a Substack user to a subscriber; is it just a numbers game?