We still need something as intuitive as Flash for developing interactive content for the web.
I was barely 11 or 12, and it was amazing how quickly i went from drawing shapes to animating them to making them interactive with simple logic back in that summer.
Fast forward to now, not sure what we have, that comes close to that level of ease of use. Maybe some game engine that exports to html canvas/webgl?
I know that it's not the web frameworks and the fragile wsiwyg editors that target them.
I know a lot of people talk about the tooling not being there, but I'm not sure that's the case. Web development is a very open field, there is a ton of documentation, and a lot of easy ways to get started. Just open developer tools in your browser and you can write Javascript - things were never the easy with flash. There's also plenty of free tools for building things with, from game libraries to animation editors, to IDEs.
I think the bigger issue is that the audience isn't there in the same way. Partly that's culturally - part of the glory of that era of internet was proper reveling in crappy animation, gross-out humour, and absurdism. But that's no longer part of the cultural zeitgeist in the same way. As a result, the cultural force behind a lot of the early examples of the medium has died out.
But also, and I think more importantly, the platforms have evolved. Animation still exists, but it looks different and tends to be hosted on YouTube or TikTok, because that's where people are. Games still exist, but now they're usually mobile games, because it turns out people like playing these games on the loo, and mobile browsers suck. And both of these platforms have their own advantages for creators: they both make monetisation easier, and they make it harder for other people to steal your work - both things that flash creators spent a lot of time worrying about.
Even as flash was dying, if it was culturally necessary to maintain, people would have done so. We had the tools and we had the technology. In fact, people did - I remember people pushing "HTML5 games" for a while, but they were never any good because no one had been making good news games for a couple of years at that point. In the end, flash died for much the same reason that non-threaded forums and IRC died - the cultural forces that used them either died themselves, or switched to other systems.
But a lot of JavaScript/web tooling is basically about making "web applications out of what once was a document framework".
Flash was more of a gateway to creative interactive content than "webapps"/games imo. MS paint -> vector art -> animation with sounds -> interactive content was that really good creative path way. Action script didn't mean maintainable code. It just meant you could easily add simple actions to various events. I honestly believe that tool alone gave birth to a lot of the cultural forces you mention.
I remember cartoon network and movie studios releasing lot more interactive websites for their content in Flash.
But you're right, a lot more content gets consumed on mobile / tablets these days than desktops, and i guess people/businesses are optimizing for that.
That company could then open source it. I even thought of the name of the company already, it should be called Macromedia.
The authoring tool that flash had was like this: https://m.youtube.com/watch?v=kHOQkooK0qY . 2 tutorials like this and you'd have everything you need to make a multimedia website
I'm currently thinking about a project that requires "regular people" be able to create interactive content for the web, and honestly i don't see any alternative.
Where it started to go bad is when people tried designing full data-oriented websites with flash and air, but i believe it remains great for its core purpose.
It might make it more useful to know what makes one off well loved flash items not currently work, or which elements are commonly used but missing support.
https://ruffle.rs/compatibility
Edit: Rereading your question, I think you probably meant to see what is missing in a specific swf. That would be quite nice.
