here's why it such a hell to climb in ranked and its so prone to streaks
When you go on a win streak, as soon as you lose a single game, you are put in a super-carry spot which mean you are gonna get shit teamates to carry for a while, you will keep losing until you manage to pull a win out of your ass, and as soon as you do, you are put in the get-carried spot, your team is gonna win for you until you manage to lose a single game and then it revert and the lose streak happen and the never-ending cycle continue. But if you arent streaking, matchmaking is just random.