Earlier quoted context omitted.
The issue is, even with all the browser protections, you still create an account anywhere or buy something an input your name/email address/shipping address, your "hashed data" immediately gets sent to meta/google as a conversion with "this guy bought a cat toy", and you start getting ads for cat related stuff everywhere. They don't even need to "track" you properly for this stuff to work and it seems there's no way…
I don't experience that though I have friends who use smartphones who describe it. So I think a lot of it is via javascript. I doubt every retailer, or even a significant fraction, has their backend sending that type of data to $megacorp. But maybe I'm just lucky or shop weird places or it's because I use a new email address @superkuh.com for every account sign up. Or maybe I'm just not seeing the targeted ads for my…
So sure, cat toy small time retailer on Etsy won't but credit card processor or shipper might.