Matchmaking is neither fair, nor working as intended.
The linked image shows my four times now (and probably a fifth time by the 12th of November) that I've made it to promos for Gold V. I've had, after the 3rd time going to promos, 2 free wins, and was not able to make it thanks to afk, and an int-ing mid lane. I have played matches where I do well, and badly. Frankly, I don't appreciate that I have to hit a ~50-60% win rate to get to promos, only to get punished with losses I can't actually offset until my win rate drops to 49%.
I won 6 of 10 initial placement games, and never faced a gold player: I placed into Bronze IV. I have been in Bronze II, I, Silver V twice; Silver IV, III, II, I 4 times, and to Gold V promos four times.
At this moment, my win rate in the last 20 games is...60%...I just failed out of promos the 4th time (with an overall of 51% win rate). I'll drop to 49% win rate, and then be given teammates who are so good, that they don't need me at the keyboard to win the game.
Why play the game? I'm competitive, I like to see how good I am...but in the context of a match-up that is genuinely a 'good fight'. This isn't even close. Matching someone up with useless teammates is not a balancing method. I had a Gold IV adc who just inted starting at level 5. We had been doing well, no one could figure out why he was tilted. He was the 'best' player on our team by rating/skill. Proved to be the loss of the game, with a bad attitude. I've had 2 times now where a guy in placements, who had reached rank 30 in the last 30 days was in my promo games...surprise, they didn't know what was going on...I've arrived at a place where it isn't fun to play. I feel compelled because I've made it to Gold before, but it is just not enjoyable to know the outcome of my promos based on my win rate.
I'm at a point where I just want my money back, so I can at least get something, since a fair matchup isn't a priority for Riot; Ranked is meant to be an approximation of a fair matchup; However, punishing players for their win rate by simply giving them inept teammates does not come close to 'fixing' the 'problem'. If someone has earned a promo 4 times, and failed to ascend, and there is evidence they didn't play their absolute worst (which I didn't in all cases)...why wouldn't they be able to make it?
The system isn't balancing in an appropriate manner.