An "agent" with access to 400 MCPs would perform terribly in real world situations, have you ever tried it? Agents would best with a tuned well written system prompt and access to a few, well tuned tools for that particular agents job.
There's a huge difference between a fun demo of an agent calling 20 different tools, and an actual valuable use-case which works RELIABLY. In fact, agents with tons of MCP tools are currently insanely UNRELIABLE, it's much better to just have a model + one or two tools combined with a strict input and output schema, even then, it's pretty unreliable for actual business use-cases.
I think most folks right now have never actually tried making a reliable, valuable business feature using MCPs so they think somehow having "400 MCPs" is a good thing. But they haven't spent a few minutes thinking, "wait, why does our business need an agent which can connect to Youtube and Spotify?"