I don't really get it. If you will fieldstrip a gun it has basically to or three points, where slide touches rails and frame. And on range I see a lot of guys overlubing their guns in thick lube.

Most of modern firearms need just a little bit of lube in key points that are prone to friction.

Also, grease is pretty good at absorbing filth from powder gasses. If you have lube in places you can't access, you will never clean your gun. That can cause malfunctions in moment you don't expect them to happen.

So if you lube - do it reasonable.