it doesn't store the purchase, it stores the email, then parses it into a list of purchases. Also if you delete the email, the purchase list remains.
Re:Reasons Not to Use Google (2015)
by beatgammit on Thursday August 29, 2019 @11:26PM
(#20835738)
Personally, I'm not a fan of email being plaintext and think everyone should use encrypted email (GPG, ProtonMail, Tutanota, etc). I think it's absolutely inappropriate for Google to track such things even if it has access, and it shouldn't have access IMO in the first place.
I don't need Google's help to search through my purchase emails. My emails are well-filtered into categories. And where that's not sufficient, search terms aren't difficult to use.
Google automatically collecting a list of purchases goes beyond what I expect an email provider to do.
Google can help you search the purchases.
If you see either of those as odd, then I pretty much don't get your viewpoint.
But sure, the next question is does Google explicitly USE that data in any other way. That's a different question, though.