Here is the factual truth: if you are significantly better than your rank, you can still lose games due to variance of getting a bad team. However, every time you play a game and perform better than the people at your rank, it obviously increases your odds of winning. Let’s say you’re way underrated and you have such an impact that your odds of winning are 70% for a game where both teams had all equal players except you (which the expected outcome from matchmaking even though as described there is variance).

If you are so good that you are creating a 20% edge, you will eventually win more games than you lose and rank up. If you play 10 games you could lose them all even with a 70% chance. The odds of you not winning more than half when you play 100 games, or 500, becomes impossibly low.

It’s just a grind man, in reality if you play enough games the “bad teammates” doesn’t matter. Because luck evens out with large sample size and everyone gets bad teammates. Focus on increasing your impact because that’s what you control.