> Now we have powerful browsers, web standards, and you can do amazing things in them
Flash had it's flaws, but it was a much more coherent interface for users and developers than what has become of the web. The mish-mash of HTML, CSS, and JavaScript (with all of the different styles of API) is really unappealing to me. It's rare, but when I do make an application out of a web page, I gravitate towards making a large canvas in the middle of a static page. This is exactly like having a Flash applet except the programming experience is worse, and animation is more complicated.
Also note that Flash was usable standalone, and in addition to having much better development tools, giving someone a .swf file was much lighter weight than the Electron stuff. Moreover, Flash had an onramp for non-programmers which is pretty sorely lacking in the web world.
I'll agree that modern web standards can do everything that Flash did, but only in that "Turing Complete" kind of way where you can do everything with Brainfuck but you'd be happier in a different languge.