What you want is online co-op campaign, however last game was always online and it was possible to do it there, but people who prefered to play it offline could not do so. So they focused making the campaign an offline experience and I think it is better so. Of course as I understand there is no online free roam mode at all, so that sucks.
Actually no you could choose to go offline on the old one but no one would do it because it wasn’t fun alone. It’s always fun to play with someone else. Or at least just make it so u have to make a party to play online campaign