Books for us are about space. Growing up, having a full-wall bookshelf was one of my favorite things. It had sentimental value, it was a family gathering place, each ripped page or blemished cover had a story. We now dont have space for a second full-wall bookshelf. We've completely stopped purchasing books and just use Kindle or the library. It works, it just doesnt have the love of a physical books. But we also dont have the space for physical books.
Living in Brooklyn, going from a 2BR to 3BR meant another $500,000 in cost. We now living outside DC, which is less expensive, but still not enough to have room.
So we rent.
Music and movies are for convenience. For me, most music and movie CDs/DVDs never carried as much sentimental value. It is great not having to carry around disks and having temporary access to a much larger library. We subscribe to Apple Music and have never looked back.