The tool use / function calling thing far predates Anthropic releasing the MCP specification and it really wasn't that onerous to do before either. You could provide a json schema spec and tell the model to generate compliant json to pass to the API in question. MCP doesn't inherently solve any of the problems that come up in that sort of workflow, but it does provide an idiomatic approach for it (so there's a non-zero value there, but not much).
And if other vendors sign on to support MCP, then it becomes a self reinforcing cycle of adoption.
Coupled with the fact that any LLM trained for tool use can utilize the protocol, it doesn't feel like much of a moat that uniquely positions Claude Desktop in a meaningful way.
This is exactly what's happening now. A good portion of applications, frameworks and actors are starting to support it.
I've been reluctant on adopting MCP in applications until there was enough adoption.
However, depending on your use case it may also be too complex for your use case.
Containers are not a big deal when viewed in isolation. But when its common size/standard for all kinds of ships, cranes and trucks, it is a big deal then.
In that sense its more about gathering community around one way to do things.
In theory there are REST APIs and OpenAPI standard, but those were not made for LLMs but code. So you usually need some kind of friendly wrapper(like for candy) on top of REST API.
It really starts to feel like a a big deal when you work in integrating LLMs with tools.
APA (Agentic Process Automation) is the new RPA, and this is definitely one example of it.