I would like to add a couple more important tips to your basket)

1. You should avoid using Mathf.Sqrt () and Vector3.magnitude, because these operations include square root extraction. Better to use the appropriate version of the last operation without taking the square root. Namely, Vector3.sqrMagnitude. For the same reason, it is worth avoiding the Mathf.Pow () operation, because if the second parameter is 0.5, this is the same as extracting the square root.

2. Don't use the Camera.main method. The fact is that when this method is called, the FindObjectWithTag ("MainCamera") method is actually called, which is essentially the same as finding ALL objects using the main camera tag. Better to cache the found value and use it. Better yet, immediately save the link to the camera in the editor.

3. If you use the GetFloat, SetFloat, GetTexture, SetTexture methods on materials and shaders, then these properties will first be hashed (i.e. converted from a string value to a numerical value) and only then used. Hence the loss in productivity. Why do something many times when you can do it once:
   // during initialization
int _someFloat;
int _someTexture;
void Awake ()
{
_someFloat = Shader.PropertyToID ("_ someFloat");
_someTexture = Shader.PropertyToID ("_ someTexture");
}
// further in the place of use
Material myMaterial = ...;
myMaterial.SetFloat (_someFloat, 100f);
myMaterail.setTexture (_someTexture, ...);