This absolutely impacts performance for JS code in general, but has no performance impact whatsoever for WebGL demos like this. All of the work happens within

This absolutely impacts performance for JS code in general, but has no performance impact whatsoever for WebGL demos like this. All of the work happens within the shader -- the entire goal of the WebGL code is to compile the shader, set parameters on it, and draw two triangles per frame. Everything else happens there. Removing all these tricks might get you -- at most -- a 1 fps boost.