The diy hustle of making mix tapes and homemade videos is how the current stars of rap, Migos, blew up.
SoundCloud rappers are a thing. It's a drug influenced, dreary subgenra that's launched dozens of stars, lil uzi vert or for example.
Everyone who told us musicians that flattening the barriers to entry would lead to more income were either ignorant of economics or willfully ignoring it further their interests. Few bands make more money off of Bandcamp then they did flogging their CDs.
Perhaps idols have network effects.
Do most people actually want independent structures? They're available to use if you do (see: bandcamp).
I assert most people would prefer a musical common knowledge (even if banal) over more interesting yet isolating music.
In a sense, musical isolation outside the mainstream has gotten worse over time, as the internet has made it easier to follow your aesthetic judgments into deeper and more disparate rabbit holes. The idea of a subculture seemed a happy medium, but these have mostly become "atomized" out of existence. There does still exist an "indie" alternate-mainstream, along with a few others, but for the more engaged music fan it's somewhat of a lonely world.
Hopefully the pendulum will soon begin to swing back toward shared experience and music creation as a means toward community-building (see: prayer), rather than as an end in itself.