Well the benefits of people living together are cheaper living. All people would help pay for the place you live in, so there’s less money spent from one person. As well as that there’s more hands to help clean and deal with chores.
However there’s less privacy more often, and you might live with people you don’t know so that can be a problem. Also there’s no telling if you like those people, so you’ll be stuck if you don’t. And there’s higher food and energy bills (although bills are easier to pay with more people giving in) but one person may be more selfish and take up more resources than others and everyone would have to pay for it together- even if one person is using more than others the payment will probably be equally shared.