There were laws requiring disclosure before GDPR and there were already tools to disable or prevent trackers built into browsers or adding on with plugins. (organic market developments) You also had alternatives to services that used the lack of tracking as a reason to choose a particular service offering over another. GDPR ended up just making these disclosures more in your face. Text like "It shall be as easy to withdraw as to give consent" is so vague as to be useless, which is why there are so many disagreeing opinions are whether companies with their current implementations are complying or not. GDPR is a bad law and in general the EU hasn't learned it doesn't get to enforce its laws in countries outside of its jurisdiction.