I read an article that dug into public GDPR cases, which is a surprisingly small set, and it explained they have had a near zero impact on the massive advertising and data broker industry. They mostly just have a large back log of legal cases against large US companies like Google which occasionally result in fines - but even that moves very very slowly and has little impact on their global business models. They do also occasionally charged a few smaller European companies a few grand for violations.

The key thing is that companies like Google and Meta run giant ad networks, there's many thousands of companies buying ads then collecting data in their own systems and reselling it.

The privacy issues of data retention on Google/Meta/etc social and SaaS platforms is something to care about but it is only a small piece of the puzzle of data privacy.

Ads will remain a major business for the foreseeable future as nobody is going to pay $5/m to use Instagram with no data collection.