I know a friend who had this said to them and they laughed it off but felt it was very telling. In their case I think the relationship wasn't an equal friendship but they were more like an unpaid support worker to this person who had severe mental health issues. Idk. Maybe this person sensed my friend was spending time with them to be kind.

I think if it were me who had it said to them I would be questioning myself and possibly them too why they said it.

I have in the past voiced to a friend that I'd like to develop more friendships but that's a different way of saying it - not like I'm saying I have no friends.