Google, GMail is storing your purchases in detail, But you can delete them, one at a time.

Google tracks a lot of what you buy, even if you purchased it elsewhere, like in a store or from Amazon. Just for kicks, I too checked my own information at http://myaccount.google.com/purchases and I could find purchases going back to 2010.
Only thing the purchases would have revealed is that I love camera equipment and I love to tinker. Canon 5D mark IV, Sony A7RII, a few lenses, LIDAR sensors, a boat load of SBCs and books.
(If you too go and check, reload the pages, information might change. It did for me.)
So naturally I went about finding more about this;
First at Google;

Where your orders come from

Your purchases and reservations are brought together from across your Google Account, from sources including:

• Orders placed using Google services, like Google Play Store, Google Express, or through the Google Assistant.
• Order receipts or confirmations received in Gmail.

To see the source of an order, select it to see its details. At the top right, select Info Where's this from?.

Delete your orders

1. To delete an order from your list, select it to see its details.
2. At the top right, select Info Where's this from?.
3. Depending on where you made the order, you can delete it by selecting Delete. Otherwise, select View Details or View Email to go to the original service and manage it.

Then in the wider web;

CNet
Last week, CEO Sundar Pichai wrote a New York Times op-ed that said “privacy cannot be a luxury good.” But behind the scenes, Google is still collecting a lot of personal information from the services you use, such as Gmail, and some of it can’t be easily deleted.

A page called “Purchases ” shows an accurate list of many — though not all — of the things I’ve bought dating back to at least 2012. I made these purchases using online services or apps such as Amazon, DoorDash or Seamless, or in stores such as Macy’s, but never directly through Google.

But because the digital receipts went to my Gmail account, Google has a list of info about my buying habits.

Google even knows about things I long forgot I’d purchased, like dress shoes I bought inside a Macy’s store on Sept. 14, 2015. It also knows:

    I ordered a Philly cheesesteak on a hoagie roll with Cheez Whiz and banana peppers on Jan. 14, 2016.
    I reloaded my Starbucks card in November 2014.
    I bought a new Kindle on Dec. 18, 2013, from Amazon.
    I bought “Solo: A Star Wars Story” from iTunes on Sept. 14, 2018.

And so on.

Then at engadget

Still, it's a lot of information that dates back years and highlights exactly how much Google can access, even when it's being used for you, automatically highlighting cards for Assistant, personal info in Search or directions for Google Maps. Also, while you can delete the entries, it lacks the abilities recently announced for Location History to eliminate info beyond a certain time period, or any kind of bulk delete button at all. You can turn off this type of tracking, according to Google, but there's no link to the controls from this page -- the company told CNBC it's looking into simplifying the settings and that seems like the right move.

GO secure your account.