Mercy is overpowered and dominant. Resurrect as an ability is not balanced. Unfortunately, if the devs want to fix this, they are gonna need to tread very carefully. Small nerf to Mothapocalypse resulted in a boycott if my memory doesn’t fail me.
They are going in the path of power creeping the support class, which i don’t think is wise. It may avoid the potential nuclear winter that a sizable nerf could bring, but it could have long lasting consequences for the game. Moira is overpowered too, but it’s not noticeable because Mercy and Zenyatta set a very high bar. Ana and Lucio are examples of balanced supports.