The way the ranked matchmaking system is set up makes it very hard to be able to play with friends if at one point during your “ranked-career” your ranks become separated. Because the game is less fun to play on your own what this means is that your rank will also move less when forced to play alone. This then makes it so that you essentially have to wait for the season to reset so you can play the qualifiying matches with your friends again, after which you are forced to wait another full season to once again be able to play just 3 matches, because the season reset seems to have absolutely no effect on rank whatsoever. Regardless of whether matches were fair during the qualifying games, the system seems to have no problem with putting one person from a party in low bronze and another person in platinum despite them performing similarly in the qualifying games.
While this may seem trivial, I believe this phenomenon negatively impacts the play-experience of lots of (groups of) players, leading them to play less of the game and therefore making matchmaking increasingly difficult. A sort of downward spiral, if you will.