This is something that bothers me a lot as, to play coop with anyone, you must create a party and wait... wait... You cannot start a mission in solo, then having people hot joining later. This is a very restrictive and old design when it comes to a coop game, and 99% of the time, when I play, there is not a single party created. And don't want to create one myself, and waste my time waiting in the hub.
Many shooters (Warframe, Darktide,...) allow to start an "open session" mission where anyone can join (well, for now you don't have the choice in Darktide but you can solo Verminitide II), then all the "bots", if there are bots, are replaced by Players who hot join. This is far more smooth than what we have here.
Do you plan to improve it or are we doomed to ignore playing coop, I mean with non-friends players?