And a lot of these dudes got priced out of the market, at least in rap music.

They were used to the era of $30,000+ producer fees, plus the back end stuff. Those days are long gone.

Instead, artists started using new producers they (or their label, management, etc.) found online who would sell a beat for damn near nothing, just to get their foot in the door and to get the shine of being on a label.

Of course, when those same producers then tried to start to monetize their music and charged reasonable rates, they got phased out and the new Soundclick or Twitter producer was brought in.

There's a reason dudes like Just Blaze or Lil Jon do DJ gigs these days instead of make beats, and it's not because they all of a sudden lost the ability to make dope shit.