Setting transform.localScale every frame KILLS framerate, 80->30fps

I don’t need to do this…but i’m completely confused as to why this kills my FPS so much? I’m just setting the localScale to some constant value every frame…and removing it recovers 80fps for my game. What’s going on under the hood that causes this to happen?

Most likely you have MeshCollider on your object (or one of the children) and you’re setting non-uniform scale. In this case Unity has to recalculate collider every time you change scale.
OR you have have deep hierarchies and you’re setting scale on a lot of objects and Unity doesn’t perform well in that case.