> I wonder why someone who knows how to do any of that, would think it is a good idea or go along with implementing that

Modern silicon valley is built off people implementing similar pervasive tracking, without it there is no google, facebook and many other startups. Not to mention online newspapers and everyone who makes money indirectly from the tracking.

I agree it's a bad thing, but that ship sailed long ago and things like the GDPR are only just starting to bring it back.