Hex Nut Manufacturers explain why screws come in many different joints
First of all, because the contact area between the flat and cross openings and the tool is not at the same level as the contact area between the inner and outer hexagons and the tool, there is almost no problem with twisting the inner and outer hexagons (but there are also round holes for the inner hexagon).
Furthermore, the screwing tool must be suitable, and it must be suitable (if you want to install it again, it will not be discussed at one time). Everyone will find an inappropriate tool to screw the slotted and Phillips screws at will. There are many cases (take a big stout screwdriver to unscrew the small nails on the back of the laptop), but it is difficult to find an inappropriate tool for the inner and outer hex.
Next, the flat and Phillips screws are not for you to screw hard, the force is just right, you screw them with such force, but unfortunately, the person who wants to screw them off later does not have your strength and skillful skills, and there is a great risk of screwing.
Finally, if the groove is spent or has been spent, please replace it with a new one after unscrewing it... At the same time, if it is rusted, please solve the rust problem first, and then screw it after removing the rust.