Actually “we” don’t call it “purchased”, they do. It’s a deceptive marketing practice for rentals.

Take for instance Amazon. They say they sell you a digital video, but they actually can’t, because in reality they have a revocable license, which does get revoked, thus all your “purchases” disappear. If you owned physical media, this couldn’t happen.

https://www.slashfilm.com/574053/amazon-sued-purchased-movie...