In the 70's, way before any internet databases and real-time data aggregation & automated analysis, you had to show ID to buy beer.

So what? What do you suppose that proves or justifies or excuses?

The ID served a valid purpose of controlling who had access to beer, yet did not track anyone's movements or habits or compile a profile on them or associate them with others into cohorts or allow anyone to presume to make any kinds of judgements or predictions about them.

The two things are not automatically and necessarily tied. It's a disingenuous lie to act like they are and use the one to justify or excuse the other.

Indulging in a little predicting myself, let me guess what comes next, "But showing ID for beer never prevented every single underage human from somehow obtaining beer." ? Wait it was unfair for me to assume that based on some data I just collected (your comment)?