At the end of the match; your reward, and the amount of rank you gain or lose should be based on your placement within your own team. First second third fourth fifth, with a plus or negative modifier put on based on whether your team won or lost. That way, the main deciding factor in the game is how did YOU do. Not how did your TEAM do.
It gets really boring, win streaking one day then lose streaking the next. All while using the same build, same playstyle, in the same rank range. You're playing just as well every match, doing the thing that makes you a contributing valuable member of your team yet sometimes you win ten times in a row and sometimes you lose the whole day and all your progress gets stolen away. Because it's literally all random, did you get put on the team with more or less good players. You are just one player, there are nine others in the match. No matter how good you are the outcome is determined by the sum performance of all ten players. The only way you could consistently influence the match in your favour against the entire performance of the nine other players in the match is if you're using a build that's so broken it literally makes you unstoppable. Which shouldn't be possible anyways.
In a game with nine other players in every match; your individual choices are not the game changer. There are nine other people individually influencing the outcome. If your team isn't good, you lose; if your enemy team isn't good; you win. Regardless of how good you are at the game, if your team is that bad or the enemy team is that good it will override anything you can do. Yeah sometimes you will make the right choices at the right times and that sways a balanced match into your favour but that's only with a somewhat balanced match; which do not happen very often, and only some of the time will you even have that opportunity. The logic that you winning or losing is based off your choices in a game of ten people is impossible, because by that logic that means the other nine people also can make the game win or lose by their choices. Which means you only won because your enemies all made worse choices then your allies. So the outcome was still influenced by the sum of ten players; even when using the ridiculous insecure logic that your individual choices entirely determine the outcome and thus if you lose oh it's all your fault and those nine other players had nothing to do with it.
Being good at the game literally doesn't matter because there's so many other players in the match that even if you're bad, if you get put on the better team they can still easily carry you. While if you're good, being put on the worse team doesn't matter because you physically can't carry all of them at once against a better enemy team.
At this point the ranking system might as well be grading who is the luckiest, abuses the most scummy class pairings with the duo que; and or uses the most hot meta that is so broken it literally can win you the entire match over the nine other players in it. Yes, some people who read this will just try to make up excuses to perpetuate the illusion that the one out of ten players in the match is the sole one influencing the outcome as long as that player is specifically them. Since if they accept that winning or losing is out of their hands then they can't claim credit for all their wins and generate ego from it.
Doesn't change the fact that this system is fundamentally based off coin flipping whether you get the winning or losing team regardless of whether you yourself are a good player or not.
And after a thousand a five hundred games that's my biggest complaint about this whole system, is you are rewarded based on the coin flip and not your own performance. I don't especially mind going on random, asinine losing streaks. It's the fact that the game steals days worth of rank progress from me while it simultaneously is the one putting me on that losing streak. Just makes the entire process feel totally pointless and miserable because it honestly just is.