The objetive, observable outcome is that before the law, websites don't have cookie banners. Since the law passed, they do. And they make the user lose time, and make navigation much more cumbersome, sometimes even impossible (not even 5 minutes ago, I had to go back on my phone because a newspaper article went into an endless loop after accepting the cookie banner).

It doesn't matter much what happened behind the scenes to cause that outcome. From a black-box perspective, it could be that

(a) the EU mandated the cookie banners, (b) the EU mandated to provide cookie settings in some generic form, and websites decided to use banners because it's easier, more lucrative, or even to put people against the EU, in spite of having other options that were better for the user. (c) the EU mandated a different thing and the annoying banners don't even comply with the law.

No matter what the case is, the fact is that the EU made the WWW worse with the law. Either due to an outright harmful law, or to a well-intentioned law with too many loopholes, or to a good law but lack of enforcement. Doesn't matter much for the end user. When you make laws that affect people's daily life, good intentions aren't enough.