Every single website seems to have a slightly different layout for the permission manager thing, even when the software for multiple websites is (in name) the s

Every single website seems to have a slightly different layout for the permission manager thing, even when the software for multiple websites is (in name) the same software developed by the same company. Why? Tricking the user into accepting something they wouldn't want to seems to be a major reason. It drives me nuts. If there was a single permission manager whose layout is controlled by the Firefox devs this wouldn't be a problem.