Yes, pocket lint adheres to sockets even more than to a belly button.
I've had quite a few people come to me with a complaint that their iPhone would no longer plug in, and generally it only takes the application of my very special tool (a bit of tie wrap) to mine a usually very impressive amount of crud out of the socket to get it all working again.
That said, I don't know if USB-C devices have the same issue. Anyone?