People keep forgetting that the vast majority of Google's revenue comes from ads. They're literally an ad company, that dabbles in cool tech as their 20% project.
If Google is phasing out 3rd party cookies, they're not doing it for privacy, they're doing it because they've figured out how to track people without them. And they don't want their competitors to do the same.
Thus: Remove 3rd party cookie support from their market-leading browser to hobble competition.
