So many excellent points!
A lot of it comes down to the ultra-exploitative form of capitalism that this particular semi-freelance model is using, though I'm sure it's not the only thing to 'blame.'
I'm self-employed outside of Medium/blogging, and my wages there have taken a hit with the cost of living, so it's not only Medium. (And I would be so pleased if I could get $120 a month from here!) Still, there are simple things the site could do to improve things, if they so wished - currently, though, the only way forward is to carve our own paths (imho.)