I'll give you a short reply, as another person who finds MCP very useful. I think a big gap is that MCP's are often marketed as "taking actions" for you, because that's flashy and looks cool in the eyes of laymen. While most of their actual value is the opposite, in using them to gather information to take better non-MCP actions. Connecting them to logs, read-only to (e.g. mock) databases, knowledge bases, and so on. All for querying, not for create/update/delete.