… But there would only ever be one case in the first place? Because once FOX won it applied to everyone else too? There was never a need for additional cases, they all benefited.

Lol no. That’s not how the real world works. Fox News didn’t establish a precedent by “taking a whammy” on behalf of the rest of the mainstream media so they could all lie freely and thereby ending all potential litigation against media outlets. They just successfully defended themselves. The reason Fox News is the only outlet to mount such a defense in court is because they’re the only outlet that’s consistently, and verifiably, lied under the auspices of “entertainment” and been sued as a direct result.

Do you understand that “the media” is not a monolith? What Fox News does is not automatically true across the board.