There's just so few things that people actually watch multiple times. The things that people actually watch multiple times tend to be the same handful of movies and shows that rotates over the years. To do that you only need a very small library. Having a large media library is mostly just waste of space, even if it's digital is wasted because you're unlikely to watch 90% of it after the first time.

But, for me at least, not only having media when I'm at home is the real benefit. Not everyone wants to manage their own media server with remote access and the eventual debugging that follows with it.

I think if you're someone who really enjoys watching movies and likes watching multiple times then buying media is absolutely the way to go. But most people turn their brain off and just zone out to whatever.

For music I'd there is way more of a case for buying media to be the dominant way to consume music since your always listening to music over and over.

Then sell it on ebay. Used dvd box sets still go for ~80% of new.