IMO MCP isn't totally dead, but its role has shrunk. Quoting from my post [1]:

"Instead of a bloated API, an MCP should be a simple, secure gateway... MCP’s job isn’t to abstract reality for the agent; its job is to manage the auth, networking, and security boundaries and then get out of the way."

You still need some standard to hook up data to agents esp when the agents are not running on your local dev machine. I don't think e.g. REST/etc are nearly specific enough to do this without a more constrained standard for requests.

[1] https://blog.sshh.io/p/how-i-use-every-claude-code-feature