How do you know that Mark has no friends?

I would guess he has zero friends by the way he sees friendship

Game theory?

He likely has people pretending to be his friends, much like the AI friends he proposes.

That he thinks that this is a good idea would be a pretty strong indicator, in that it implies that he doesn't grasp, at a fundamental level, what friends are.

Agreed. He's projecting.

Zero substance on these comments.

Look he is richer than everyone else he knows. He hangs around with employees all day, they are subservient to him. He doesn't know real friendship because all his relationships are with his wealth.

I highly doubt an uber successful guy like him has no friends