For sure, mass marketers prefer quantity to quality. Google/Facebook are not doing anything particularly novel in the realm of what is possible, nothing more than is needed to get accurate enough across a large number of users.

It's the more targeted uses of fingerprinting and data collection that are scary. If you're a person with lots of money or influence, there's already someone out there who is specifically trying to collect data about you in particular. Those people and organizations are looking at the data in much more detail than mass marketers.