You can ask an AI agent that question and get a very comprehensive answer. It would describe things like the benefits of adding a wire protocol, having persistent connections with SSE, not being coupled to HTTP, dynamic discovery and lazy loading, a simplified schema, less context window consumption, etc.

Yep. And those that did implement the standard did so for a different set of consumers with different needs.

I'm also willing to make an appeal to authority here (or at least competitive markets). If Anthropic was able to get Google and others on board with this thing, it probably does have merit beyond what else is available.