It is categorically not wrong. With an MCP you have at a minimum all the same dependencies and on top of that a dependency on your agent supporting MCP. With skills, a lot of the time you don't need to ship code at all - just an explanation to the agent of how to use standard tools to access an API for example, but when you do need to ship code, you don't need to ship any more code than with an MCP.

The trivial evidence of this, is that if you have an MCP server available, the skill can simply explain to the agent how to use the MCP server, and so even the absolute worst case for skills is parity.