For starts, MMA coverage has never been very good.
When MMA was a fringe sport for weirdos it was covered almost exclusively by independent outlets (sherdog, bloody elbow, etc...).
Now it's covered in major outlets, but treated as a 2nd tier sport. It's not prioritized, it's largely fill and fluff pieces, and often covered by "journalists" with no actual knowledge of the sport. The best people are just carried over from the smaller indie outlets.
"Access journalism" is stifling scrutiny. "Journalists" who glowingly cover the UFC and reprint press releases nearly verbatim are granted access and given better info. Jornalists who ask hard questions, dig out stories the UFC doesn't want fans to know or doesn't want them to know yet, critically cover things... they are going to farce barriers trying to access fighters, execs, events, and info. So most will go along to get along.
Then there are the conflicts of interest. A number of large outlets have financial ties to the TKO/UFC/Endeavor/Ari Emanuel. Outlets will catch and kill stories that conflict with their financial interests even if it's in the interest of their audience to know.
Lastly, low information fans who don't understand the difference between editorial content and journalism can make it easy to bury an actual story. If a journalist talks about something the UFC doesn't like they don't need to counter the story, they just need a dozen talking heads to spout nonsense that kind of bury the story. Make opinions sound like facts, facts sound like opinions, make the opinions the story itself.