For starters, Google: https://www.google.com/#hl=en&q=major%20labels%20invest%...
Doesn't take long at all to find out that the deals struck with majors included not a decent percentage, but actually ownership. Ownership means access to a revenue stream — good for labels, bad for artists who don't receive royalties on investment revenue.
Go beyond that one Google search, you can quickly learn that indie labels — the folks who win more than half the Grammys — don't get the same arrangement. So the music one their labels actually subsidizes the competition. They're not all that happy about that.
And lastly: artists. You can listen to them. Plenty are outspoken. For every Metallica getting onstage with Spotify there are many others essentially saying that they receive nothing — and that makes sense because the payouts are designed to work at scale, not at the level most working musicians operate.
Saying all this without judgement. I think the streaming market could be a good one for artists if it were more geared to driving direct purchases — but thinking about it as the answer is a problem. It's the start of exposure, like radio used to be, not the end goal.