There are other real reasons for this happening people laid out, but part of it is that...the prevalence of "kids" media in whatever forms are available is a generational trend that ebbs and flows. Not to say there wouldn't always be something kid-friendly, just how bigger picture trends shake out.

90s parents were bigger on "subversive" entertainment where the appeal was pushing boundaries they'd realistically not want kids in on. But my parents would scoff at a fellow adult watching Pokemon with their kids. This era's been more about legit "fun for the whole family" content like Marvel, etc.

People vastly underestimate how much WWE's popularity has reached out worldwide.

It's bordering on transcending being a banner American wrestling show. Getting into territory like say, Cirque du Soliei or something. It doesn't matter that much anymore if it's a niche thing back home, they can go just about anywhere in the world and draw humongous crowds just because it's an attraction in and of itself.

This might not sound like a huge deal, but one of the big consistent things Vince McMahon has done over the years is buying up the tape libraries of just about any rival or defunct wrestling promotion you can imagine. At least US ones. So you aren't just getting the rights to WWE's massive well of their own content, it's basically buying the rights to decades of wrestling history to boot.

That plus the fact they have a lot of investment in things like their own film production arm, stuff like that...even if Star Wars is more popular than WWE today that doesn't always translate to being worth more as a whole bundle.