No, the carry-on is a piece of luggage that can be stored in the overhead compartment (assuming there’s room, hence the waiting in line). In addition you can bring a personal item (backpack/purse). It’s those bags being put up top as well where the dick moves come in since, on a full flight, there’s not enough space up there and the passengers who boarded before you have put BOTH their carry-on and personal item up there.