If they had more info, they could avoid blanket policies such as avoiding riskier shipping options with all new customers, and use with customers they can prove are not fraudulent.
But here's my anecdote:
I bought a metal collar extender at Macy's with my credit card. It was an impulse buy at checkout and I have never searched, emailed, liked, etc. this product in my life. I get on Amazon a week later and I have a recommendation carousel of metal collar extenders. I was so surprised I even checked my email for a receipt to see if that's how Amazon retargeted me [there was none].
But then I just stopped caring, because I realized that if anything Amazon was incurring an opportunity cost for not recommending me something more useful, and I have more important things to do with my time than to worry about how I'm being retargeted on Amazon.