I had a formative experience with Flash as a middle schooler. I loved Albino Blacksheep, Newgrounds, etc. I thought the videos were hilarious and the stick-figure-style animation was approachable. So I acquired Flash, and I was blown away by how easy it was to create these silly animations. Automatic tweening was a miracle to me.
Since then I've done a lot of video editing with different tools, but I still think back to Macromedia Flash and how I, a child with no ability to code and no knowledge of HTML or Web tech, was able to make my imagination come to life on the screen.
I believe it's that powerful experience for novices that we're missing. I'm not sure how we should get it back.
(edit: phrasing)
Disclaimer: I'm an old git.
I think you have deftly described a bigger problem, as the whole industry gets more and more sophisticated and complex. The barrier for entry is so high now that I think it stifles young people's interest too quickly.
The great thing about Flash was the developer tool. Part animation studio, part simple programming IDE. It was a great balance.
Maybe there is a place in the market for framework to implement a flash-a-like in a HTML5 Canvas?
And ruffle-rs[2] is a reimplemenation of the flash player itself in Rust. (So you'd still be using ActionScript for authoring)
[1]https://www.openfl.org/ [2]https://github.com/ruffle-rs/ruffle