Hey
This idea has probably already been posted, but I'm submitting it just in case.
The idea is to create a matchmaking room. When you click play, you arrive at a list of games waiting for one or more players. You can either click on a game to join, entering a waiting room where the game leader can choose to invite or decline you. Or you can create a new game with options such as dungeon selection, minimum item level, desired classes, etc.
I know it can create a Gatekeeping but it's annoying to leave party because the dungeon selection is the wrong.