sam henri gold, as someone whose life would literally not be the same without flash, I have to point out some good things about it.
- The ease with which it allowed people to create rich, interactive, animated content, with little to no programming, is still unmatched to this day. It was ridiculously easy to get into it. We even were taught how to make flash animations in school. It allowed one to just start drawing crap without getting mired in programming.
- The standard is open. The specs for the SWF file format are freely available. It's just that there was one crappy proprietary implementation of its player at the time when it was most popular. That was unfortunate. There's nothing inherently bad about the SWF format itself.
- It offered a very clear boundary between the document and the application. Don't want websites assaulting you with sound and autoplaying videos? Just make flash require a click to load. The current approach with putting everything into the browser itself with no end in sight is atrocious compared to that. You can no longer separate the application from the HTML document. You can't even make the browser forget what a <video> is for certain sites, which would've been an extremely useful feature these days. User agent, my ass.

But Ruffle is a thing. It's incomplete for now, but the progress is happening rapidly. I sure hope flash makes a resurgence.