I am sympathetic to the idea that the revenue share isn't great, and I also agree that there are anti-competitive practices, and the market would do well with more competition. But i do think its the wrong starting point to believe views or listens on these platforms should be enough to sustain a creative career for most artists.
As you alluded too, even amongst the most well known musicians they make a lot of their income from touring, my perspective here is that these platforms when well used give you exposure, then with a linktree / beacons link an artist can develop a relationship with some of their audience that provides further opportunities to fund themselves.
Its a great question to ask when the "exposure" benefits the artists more, and when it benefits the platform more, i'd personally love to see some quantitative analysis of that. My suspicion is for most small artists with audience sizes of less than 100k people (in the west, the calculus is probably different in the rest of the world) the benefit to the artist is really great. For someone like Taylor swift it benefits the platform more, but at that point she can negotiate directly