Because... Google's business model. Your ability to see your purchase history on a Google page is neat, but it seems a safe bet that the real reason they want

Because... Google's business model. Your ability to see your purchase history on a Google page is neat, but it seems a safe bet that the real reason they want your purchase history is because their profile about you as a set of eyeballs becomes more valuable allowing them to charge higher rates on ads. Notice that they only claimed to have stopped scraping gmail for ad targeting purposes, not that they stopped scraping period.