Google Play Count
Here is a way to track your google play count. It won’t give you a full list of movies but will give you an accurate count as far as we can tell.
You go to: https://myaccount.google.com/u/0/yourdata/youtube?
Under YouTube Dashboard, click on more.
It gives you a total of purchased videos.
Thank you to @The Nethy Warren and @Ash UK
You can also get your history directly from Google Play
Go to https://takeout.google.com/
Select Google Play Store (Not Movies and TV) and create your export. It should not take very long.
Go to your export on the takeout page and download it. If you need to change it to a csv file to open it, you can use https://json-csv.com/ or https://www.convertcsv.com/json-to-csv.htm
Open it in your excel/google sheets/whatever program you use
You can see your purchase history, library, etc. You will need to sort through it but the data is all there. Purchase History is probably the most useful here, use some filters.