The issue is also that the cookie banner has become a meme for non technical "deciders". That means even sites that do not track you will have the banner.
How is such a banner even supposed to work when there is no choice for the user to make?
I mean, someone has to make that banner, so it's quite a way from the rash decision to its execution, where at any point (preferrably immediately) someone could and should step in and say "we are not required to do that and we should not spend any money on it". In my experience, non technical deciders are often sadly under-advised, sometimes because tech people who might know better fail to communicate even very simple facts like in these in an understandable way.