Because 90% don't even do anything? It turns out it's actually one of those really annoying problems to delay cookies which were supposed to be sent already in the HTTP request response until a user interaction has happened. And on a lot of pages, non technical people embed random 3rd party resources. And these 3rd party resources might claim to use only "technically necessary" cookies, but of course that's nonsense; I'm not visiting the 3rd party.