A couple of scripts that helps you optimize the non primitive 2D Colliders in Unity (Edge Collider 2D and Polygon Collider 2D). You can change the level of optimization in the Editor with direct feedback in the Scene View (see the GIFs) to find a suitable compromise between performance and good approximation of the sprite shape. Usually you can loose quite a bit of points with virtually no change in the polygon contour.

For the Edge Collider it should also be said that it creates a good edge collision shape for you which doesn't happen by default in Unity.

At this point you can also get the latest package from the Asset Store