What's the alternative for the authors?

Streaming services could price themselves out of the market in an attempt to generate the income needed to pay artists fairly. (Google/Apple could temporarily draw money from coffers and outcompete Spotify temporarily)

Or artists could sell the music directly at a fair price (no streaming service but vinyl or downloads). Or more people could go to concerts

Either way, consumers need to pay more before all good artists can make ends meet. The (comparatively) pocket change that many of them get from streaming won't be enough even if Spotify turns into a non-profit and improves payout from 70% of their income to 99.9% of their income

Most consumers seem to disagree, judging by the reactions to Spotify's recent price increase in the netherlands (even though the increase was lower than inflation or median income growth). With the money simply not being on the table unless you get lucky and get massively popular, there is no realistic alternative, but some options feel more fair than others. I could totally see myself doing music as a hobby and seeing what I can sell on Bandcamp rather than supporting Google and having them/Youtube stream my music to people

Bandcamp, for one. That's the easiest, biggest, smoothest.