> EU law requires you to use cookie banners if your website contains cookies that are not required for it to work.
No it doesn't. EU Law requires you to not harvest data at will, and you either must have a basic functional requirement (i.e. 'remember my login'), or you must ask the user if you can have their data to profile them so the advertisements can make a few percent more money (yes, the whole profiling thing doesn't even add that much to the bottom-line!).