Amazon doesn't directly sell you the AWS infrastructure. But they rent it to you. Google is doing something akin to that. If they had an opt out saying "Don't use my private data to show me ads" I'd no longer make the point they sell my data. But they don't provide any opt-out, and the effect is identical to my data being sold to advertisers.
If a company sold your information, you can say bye bye to being able to restrict what that information is and who has it; you might as well consider it public from that point on. I don't think anybody in their right mind would call that difference a technicality.
Google does provide the opt out you say they don't, too: Browsing in incognito mode.