You seem to forget DQ's main issue; ridiculous queue time mechanics.
I understand, going Fill (support) or support will result in almost instant matchmaking... cool. Go anywhere else besides perhaps top and more often than not you are going to take 10 minutes to just get into lobby and god forbid someone dodges queue. I think it's frustrating. League's player base is obviously large enough for near instant matchmaking. Remember solo queue? It would take 2 minutes tops to get into lobby and as often as not you'd get your preferred role anyways. When I have an hour to play I don't want to spend 20 minutes getting into a match. This is my only real beef with DQ. Toxicity is down in my opinion and facing groups has largely been a non-issue of late at least in my elo.