I think buying a DvD is the perfect analogue here. You own the shiny disc, you don't own the contents on that disc.
We're just taking away the shiny disc in the digital era. It's not a perfect term, but for 99.999% of people, "indefinitely rental for years until the servers die", would associate with "buy".
But in the dvd case you don’t expect someone to effectively repossess your dvd a couple years down the road without reimbursing you. You don’t own the content but you do own your dvd which allows you to indefinitely watch the content.
