Each artist is a company that produces music as their product. There is no set rule book for how they need to distribute their music to their fans and to the world.
Yes, music is art and art has value. However, when it comes to art, the value of it varies greatly from person to person. "One person's art is another person's treasure." With art, compared to other products and services, the value it brings to someone and the way the product is utilized is personal and unique to an individual.
Look at visual art, specifically paintings. There are some paintings that a person would buy for thousands of dollars that another would call hideous. Art doesn't have an "intended use" or "utility."
So what's the point?
In this sense, there is a lot of debate over whether music should distributed via streaming services or whether "high demand" artists' music should only be available to paying subscribers. I believe, it is up to the artist how they want to deliver their art to their fans and it shouldn't be universal that everyone has to go through the same supply chain. There are always going to be artists that want to distribute their music freely on streaming services and they are free to do so. On the other side, there are artists that want to focus more on getting the most sales and are large enough that they don't need streaming services to get their music heard. They have the right to only make their music available for purchase.
Although I believe it is up to the individual artist, it is my opinion, that artists should make their music available via streaming services, where an ever growing number of fans are heading for their music consumpion. At one point in every artist's career, they need to rely giving their music away for free or playing for free just to get noticed. The people that first noticed them and helped spread the word became their most loyal fans. I think it's important to keep that mindset and not forget where you came from.
Music is special and has value, but your fans and the sharing of your music with them to bring everyone together is even more special than the actual music itself. There are plenty of talented artists who create great music, but no one knows about it! Truly make it about the music. If you and your music are really that popular, you will be successful.
No matter what, fans can get any artists music for free and the artist won't get paid aything. Streaming services allow artists to earn royalties on the free listening and are working to convert consumers into paying customers again.