Artificial scarcity is good for business. When the old stuff disappears, the new one sells better.

As an example, I recently started listening to eurobeat. I looked at Wikipedia and found that there is a CD series called "Super Eurobeat", which already published 250 volumes, containing about dozen songs each. Think about this again -- there are about 3000 songs, all of them already selected as "best of", just from one genre I previously didn't know about. Given that I don't spend much time listening to music, it might take me more than a year to listen to all of them; and after that point, I would be happy to start from the beginning again. So, from my perspective, it is not necessary to make new music, ever. And if we lived in the kind of world where copyright expires let's say after 14 years, most of that would even be legally free. And the same is probably true for most other genres.

Ok, this is extreme. New things are cool. But the more you are aware of the good old things that exist, the more work it takes to impress you. You will still be impressed with great new things, but much less with average new things, especially if they are expensive. And I suspect that the average new things make the largest part of the sales.