> Don’t underestimate the reach of billionaires with an ideological agenda.

Or the audience's need to have their wrong opinions validated.

Fox News has been the #1 rated cable news network for over two decades. They've had more viewers than CNN and MSNBC for most of their existence. Calling them anything other than "mainstream" is just supporting their propaganda. They've always branded themselves as the scrappy outsider because it plays well with their audience, not because it reflects reality.