They realize that there's no magic; all it takes to make something nice is a little knowledge, and a lot of work.
From what I've seen of Fortnite, it promotes a different kind of creativity, which is more like creative problem solving (boxing people in, riding rockets, etc.) But it does have a sandbox mode that I've seen some interesting creations from.
It's a great animation tool with a great learning curve, I'm surprised Adobe isn't doing more to get it in the hands of teenagers^w young creators.
And on that point it seems that Flash helped to kill itself by accelerating ubiquitous web video.
The 2D GUIs of many 3D games were written in Flash. There are non-Adobe Flash players which can be embedded. The advantage was the authoring tools - the GUIs could be elaborate and graphical without much effort.
I think an interesting part of my experience was that it started with watching. I just loved the videos and thought they were hilarious. I admired the people who made those videos and I wanted to join that circle of creators. And Flash didn't prevent me from doing that. Not only that, but it was a specific low-effort style of animation. The path from consumer -> producer was short.
So really, I think you have to look at what people are consuming, and then try and make it easy for them to "participate." I'm not sure if people are consuming Flash-style animations anymore. (Maybe they are, and I just aged out of the demographic.)
It seems like a lot of that creative energy has moved to sandbox games like Minecraft for now, where that community of creators and would-be creators still exists, and away from animation and Web design.