I mean it could allow you to send multiple smaller payloads to the asteroid and allow it to act as a central ship. You can carry a smaller payload either way if you could figure out how to mine and manufacture on such a body. You wouldn’t need the object to be as heavy with shielding materials etc. If the project was sophisticated to carry humans you could develop essentially a colony and sensory instruments once actually on the asteroid. You could mine for elements and there are many.