The music industry does a lot of things, many but not all of which can be done easily nowadays. It gives advances to musicians. It provides sound editing ability. It encourages some. It's very corrupt, but it isn't useless, and I don't think modern music can thrive without some of the things. If you don't like that analogy, consider books. A great book is a product of a great writer and a darn good editor.
Forget the stuff about the artist driven to create. It is real, but it isn't complete. For every great movie-maker, there's hundreds of people who want to feed their families and pay their mortgages working on somebody else's creative vision. Art, in its various forms, would exist if it wasn't commercial. It wouldn't be the same, and it usually wouldn't be as good. There's plenty of obvious exceptions, but they're spread out over centuries.
I have favorite authors. I like them to make enough money that they don't have to worry about the day job, and also provide incentive to write more and better stories.
All of this was financially based on the fact that only the publishers could make good physical objects incorporating music and stories. Now that copying them is easy and almost free, they need to find other ways of getting revenue. For that matter, we need them to find other ways of getting revenue. I've heard various schemes, but none of them work as well as paying the author or musicians a cut of every copy somebody wants.
The purpose of copyright, in the US Constitution, is to promote the advancement of the useful arts by granting a limited monopoly. Like many things in the Constitution, it specifies a purpose and things the government may do to satisfy it, and does not get into details. Spreading the costs among many people, which is easy to do if copyright can be enforced, works for the purpose and is consistent with the means.