Psyonix has let this game deteriorate massively. Since f2p, smurfing has gotten completely out of control and as a result the ranking system is a total joke.
I've soloq'd to Grand Champion in multiple playlists, and have lost just about all enjoyment that I used to get from the game.
They've been given dozens of solutions on all of the forums, but take zero action.
Games at or around GC level (around 1500 elo) vary in quality from what feels like 1000-1600, so you may as well just toss a coin at the beginning of most games and spare yourself the 5 minutes of mismatched BS.
Chances are that your playing against a 1700+ GC on a fresh account who's boosting a useless mate, or his useless mate has been carried up to a rank he can't compete in by himself days prior and has landed himself on your team. In both instances, it's a waste of time.
It's extremely sad that it's gotten to this point now as the core of the game is brilliant, it's the community and the developer's total lack of interest that is killing it from within.