You mean like Netflix recommending movies or drama you may be interested in based on your past views? So I guess the French regulators are next going after Netflix, Disney, HBO, etc.?
I'm not familiar with the French regulation. Also, Apple is appealing the decision which means they feel there is at least a chance to change the results.
And there's unfortunately not enough technical details (in English) to really understand the finding of the court in terms of an outsider. Including, whether this was based on GDPR or a France-specific law.
So I can only speak in terms of GDPR - if Netflix is building a profile in order to provide a service, they have to disclose that the the user but can do so via something like a EULA.
If Netflix wants information not needed to provide their service, it needs to be opt-in, must be capable of being opted out of, etc.
Facebook got slapped recently with GDPR because "serving relevant ads" was not part of the core service from the user perspective of "message board".
AFAIK, Google has been doing this all the while. It did not start only recently.
Google has their own problems. They take a much less legally-guided tact to policy changes, which tend to get them in trouble that Apple does not get into.
AFAIK, ATT is designed to stop tracking across services, not within the same service.
Again, my less-than-attractive take is that this was the result of a French lobbying organization whose members were impacted by ATT. I would agree that it doesn't make sense from a two-wrongs-don't-make-a-right perspective, but it does make sense from the perspective of companies that are worried that Apple is being hypocritical, and will attempt to take advertising revenue from them.
It is also worth noting that there is a substantial amount of app advertising which feeds into the App Store, and the device identifiers were used to track conversion and overall effectiveness of programs. I can certainly imagine this was actually about worries of Apple getting into the in-app advertising business and wanting to apply a lot more scrutiny.