He'd Rather Be "Raped By Pirate Bay" Than Played On Spotify
torrentfreak.com
torrentfreak.com
So if you have music you want people to hear, you need to get it on the radio, get it played in clubs, have it reviewed etc. Most people don't _hunt_ for music, they find what they like passively. So if you want more ears, you have to work to get the music in front of them.
That takes expertise and time. Artists don't necessarily have either -- not if they're giving the music the time it deserves.
Hence labels. They understand marketing, have money to pay for studio time, handle the technical details -- engineering, mastering -- and have the distribution channels.
I don't know if I'd go that far, but I will say that the absolute best performing advertisements are for competitors. Thankfully, my free competitors have mostly not figured this out yet, and think that their yearly AdSense check is webmaster welfare instead of an indication that charging money is working for somebody.