Matchmaking wouldn't speed up anything. This isn't an FPS where there's only a handful of basic game modes all played roughly the same way. There are dozens of different monsters, at different difficulty levels, and people looking to do different things with them (speed farm, resource gather, cap, advance HR, etc).
The online system is terrible. Why are people defending it? It'd be better if you could just pick a rank and monster and be taken into an available room. As it is now, you have to look through pages of full rooms before you find an open one, just to get the "could not join room" error most of the time.
Then the problem isn't the lobby system. It's the lack of filtering out full rooms in the search options. Seriously, what's the point of full rooms showing up in the search results? You can't join them anyways.
It should filter options and have an auto join option. You could look at the list just like now (but it would only show rooms with space. it would also update the list every 10 or so seconds). If you select auto join it just throws you in the first available room prioritizing whatever you have your auto join preferences set to if multiple rooms are available (similar HR, voice chat for the love of god, text chat, advanced quest, key quest, best connection, etc). Add a tag system to rooms so you can tag your room with stuff like english, advanced quest, key quest, rotation, voice chat preferred, voice chat only, text chat preferred, text chat only. Add a rank locking to the room where the host has the ability to only allow people who are at or over the rank lock to join. You can only set the rank lock as high as your rank is. Seems like it would slow things down but it just cuts down on the time people spend getting insta kicked. Also why the hell cant you edit a room after making it. That option is vital as is being able to pass host. After someone searches and turns up no results prompt them with "make a room with these settings?" and have it fill in the room creation menu with your search settings. I cant think of any reason why there is a size cap on lobbies in a peer to peer game. It seems so arbitrary and inconvenient. I love online in this game but there is soooo much room for improvement.