In the past 1 year, I think I've moved from MCP to A2A to Agent <> MCP back again. I have agents still talking to other Agents via A2A for some use cases, but for the most part, it's back to Agent <> MCP now; couple that with tool search/code mode (whatever you want to call it) in your Agentic AI harness, MCPs seem to be the way to go for now.