I'm not comparing Flash to WASM—I don't care about it, I don't use it, I'm suspicious of why people really want it. But at least WASM has a specification and independent implementations.
Regardless, that's whataboutery. Flash Player was famously riddled with security bugs. The question is [Browser + Flash Player] vs [Browser] and the answer is obvious. Removing an entire surface area—a pure subset—is always a security win.
All the down-voting is hilarious. Clearly there are still some people feeling quite raw about the loss of this proprietary web extension. If you think I'm wrong, please tell me about it.
I'm 100% on board for projects like Ruffle to exist for reasons of archiving history.
My objection is only to people who in any way lament the death of Flash. Consider that nobody is scrambling to build a clone of the Netscape Navigator 4 parser and renderer. The fact that this project exists is testament to its importance for a brief period—but also to the awfulness of the canonical implementation.
People talking fondly about flash are thinking of the way that it massively lowered the bar to creating interactive content on the web, ushering in an explosion of indie games, animations, videos, etc., the like of which the internet had never seen and may never see again. The "awfulness of its implementation" (compared to what, one wonders?) is orthogonal to what people liked about it.
Absolutely, Flash inspired a form of artistic communication. But it wasn’t as egalitarian as you imply—and to the extent that it was egalitarian, I suspect that was on the back of rampant software piracy.
Meanwhile, plenty of treasure has been found in the smoldering ashes of a dumpster fire. Rick Astley inspired an entirely new genre of comedy. That doesn’t speak to the inherent merit of his music.
There are things that were easy to do with flash, and are still a nightmare with html, like group video lectures with chat. Adobe even provided their own media server. Replicating that with html is not at all easy to solve.
And no, making “an app for that” is no replacement
So what? Flash created all sorts of usability problems. Horribly inefficient video playback, keyboard focus stealing, not responding to mouse/trackpad input the way native widgets do.
I think you're remembering Flash with rose tinted glasses. It's a scripted environment—you can make it do anything given enough time. Almost nobody ever did.
Adobe's Flex framework (now open source at Apache) made it possible to build a responsive layout in a few minutes... not much time needed at all (that's where the name "Flex" comes from). Some of the people who built Flex went on to build AngularJS at Google. There's nothing rose tinted about it -- Flash/Flex were definitely an important and positive influence on modern web frameworks.
• Proven track record of terrible security bugs
• Was most frequently used for ads