I care about one thing, and one thing only: an irrevocable right to experience a particular piece of media where and when I please in the original form it was released, subject to natural degradation of the physical medium. Now that music is digital, I expect the "when" to be "at any point in my life, starting from when I purchased it", and the "where" to be "any device with the ability to play music".

Streaming is essentially asking for permission to re-experience a piece of media every time I want to do so, and Spotify's and YouTube's answer is often "no". My music library is simply a necessary evil that facilitates security against their whims.