Spotify could not pay any more to artists. Maybe the payments would be spread more evenly but they can't possibly pay unless more people subscribe to the service. How much do Idagio pay artists?
Spotify could improve their system for sure but I'm guessing vast majority of the music listened there is between 3 and 5 minutes. Idagio is probably very different in this regard. Why Spotify pays like that I don't know but remember that the whole service was started by an agreement with the labels who also got shares in Spotify.
Spotify's system is similar to the system where libraries pay authors for the books (Finnish "Lainauskorvaus"). They pay a flat rate for each book. It's just as unfair because it doesn't matter whether the book is 50 or 1000 pages long, only number of loans matter.
There is no going back to times when you could only listen to music once you bought the album except if it was on radio. So hearing anything outside the mainstream was rare. You must remember from your youth how much rock you could hear from the radio in Finland back then.
Good, but long article on Spotify:
One thing that article doesn't discuss is why the per track pay is so low in Spotify. Could it be because people use Spotify more? If both Deezer and Spotify cost the same and people on Spotify listen twice as much then obviously per track the pay is half.
No doubt things could be better but IMO the key issue is that the whole industry, just like movies and television, is changing. Last such big change happened with the advent of recordings. Wonder what the artists thought back then? People could just buy an album and listen to it as many times they wished instead of coming to a live performance!