It's not, though. For decades your game purchases always granted you a license to use the software, as-is, in the manner they choose, and on the mediums and devices covered in the license agreement. You purchase a game, that's one license agreement. You purchase a month of gamepass, that's a different license agreement. You sign up for stadia, different license agreement. No real ownership of software has ever occurred, despite someone physically owning an playable object.
So sure, you can do all the things with the durable media that you mentioned - privately collect, trade, sell, etc. But playing the game itself means you have agreed to the terms of the legal license agreement. People using streaming services aren't seeking the additional enjoyment of owning, collecting, trading, or using physical media.