There is a generational turning going on, with Boomer driven media stars fading...However, it has less to do with MAGA than with the eclipse of Boomer cultural dominance. 100% wrong! That's not what is happening.
What happened is for 9 years now Trump has not only exposed big media and all the players as corrupt lying perverted misfits and freaks, but also exposed corrupt government at all levels.
All their corruption has been exposed by Trump! It's historic and all Trump driven! There has never been anything like it. That's why for 9 years now they wanted Trump dead.
Trump is the most consequential President since FDR. However, he does not exist in a vacuum. Over 30 years ago, Rush Limbaugh laid a groundwork for a popular version of conservatism. His pioneering work was followed by a host of others, such as Hannity, O’Reilly, Savage, and others. Remember that in the 1980s, the only conservative presence in the mass media was when NBC, CNN, etc., would pit someone like Jerry Falwell or George Will (conservative back then) against three of four liberals and call it balanced coverage of opinion. There was William Buckley's Firing Line on PBS and that was it.
You also have to consider precursors of Trump: Ross Perot, Pat Buchanan, and (to some degree) Ron Paul: people who unsuccessfully challenged the Bush era GOP. They were the 1992-2012 equivalents of the Free Soil Party and the anti-slavery Whigs, who laid the groundwork for the rise of Abraham Lincoln.