A common misconception is that as a role, healers are overpowered. This just simply isn't the case.

Healers don't climb so high because they are insanely powerful, they do so because the disparity in effectiveness between a skilled healer and one more green is massive. Plat vs silver, diamond vs gold, you almost never see two good healers face off against each other.

The main reason for this is that healing is extremely difficult, with 4v4 Feast healing being arguably the most difficult content in the game. This deters people from playing it and those that do are nowhere near as good as the veterans they are forced to go up against. They have a very low skill floor and a very high ceiling.

So again, the issue is not that healers are too powerful, it is that they are too difficult to play which leads to massive gaps in skill.