A research paper demonstrating how there’s no such thing as anonymised user data. Researchers were able to identify politicians and specific individuals based on just a few data points.
The only way to get anonymous data is not to collect personal data at all, use differential privacy (add noise, sampling, choose hours instead of minutes), and do on-device processing.
Detailed personal data is a bad predictor of conversion anyway so you're just collecting legal liability. My age, name, location don’t strongly correlate to my cat ownership (cat toys), upcoming stag do (fancy dressing), or food preference (roast). No wonder adtech conversion rates never go beyond 7% and often sit in the 3.5% – as good as firing a shotgun in an open field.
An exception would be spending millions to bombard users with your propaganda in the last few days before a vote, but we don’t talk about that.