It exists partially because many great games, for a long while, before widespread internet access, could not be played if they were no longer directly sold without either paying out the nose for a working, used cart or disc, and console... or via emulation, which is apparently basically illegal, in practice, technically, its complicated, etc.

Then the video game landscape changed with widespread internet access, much more oriented toward what used to be seen as buying a fancy pants board game into well now you're just buying a ticket to a fancy pants board game that can be revoked at any time, and now you just have an expired ticket to a box that is magically superglued shut and will light on fire if you pry it open.

Some of us olds still view software as a product, a good, not a service.