You don't. Didn't they tell you? Once you get to plat...the game turns into a pissing contest of who can hold out picking a healer or tank the longest.
No one has como understanding.
No one wants to be a healer. And everything thinks they're DPS gods.
My highest SR, this season, is 2727 and I can't seem to climb past it.
...Even when I change to a healer because my whole team refuses.
...Even when I carry, as a tank, with 4 gold medals.
My patience with competitive has dwindled as fast as my SR.