In the gaming arena, you can look at http://html5games.com/ or http://www.kongregate.com/html5-games or http://www.html5games.net/ or even just Google "HTML5 Games". Based on all of those HTML5 games it's clear that HTML5 can replace Flash in the gaming arena. There's only 1 place where HTML5 games and Flash games are really that different - on mobile devices (Flash doesn't work well if at all, HTML5 works like a charm).
As for animations, doing some simple Googling will bring up results that also show HTML5 can replace Flash: https://www.freshdesignweb.com/examples-html5-animation/
HTML5 doesn't replace Flash. It's certainly an alternative, like my engine is an alternative to LÖVE, but it doesn't replace it. This is akin to saying SDL replaces lwjgl, or Unity replaces UE4.
HTML5 without WebGL doesn't match the functionality offered by flash, even for just 2D content.
HTML5 with WebGL runs fairly poorly on a lot of machines, and not at all on many as well.
I'm not really sad to see flash go (though I truly hope there is a way to preserve it's content, and would be very sad to see that go), but HTML5 is a ways off from providing the feature set and reliability of Flash.
That's Flash's domain predominantly, and that's what it does best out of its feature set.
But I see your point and expect HTML5 to improve, but it is along way from being what a lot people think it is.
That would be because Chrome on iOS is not Chrome, it's a wrapper around a UIWebView with all the performance pitfalls that entails. Go try it in Safari on iOS or Chrome on Android if you want a proper performance comparison.
The world has just changed around Flash. The performance and security problems, which were an annoyance 7 years ago, are today seemingly fatal--not least because Adobe has spent 7 years trying to fix them and failing.
At some point it seems like we should just throw up our hands and invoke the sunk cost fallacy.
Flash needs to go for the sake of our security, not to climb up to a bleeding edge. The security risks are way beyond unacceptable.
Perhaps you could argue that some similar functions in HTML5 have just as serious of threats but additionally lack an off switch??
As for accessing legacy content, treat Flash like Ebola and keep an old machine around for that? It would help if the old machine has no writable flash or drives (or at least includes a non-writable restore image if there's a drive).
If our machines have writable flash for the network adapter, video card, hard drive, bios, and a few other things, how secure can they be? Even our flash isn't safe from Flash.
What about the game industry? What about the animation industry? HTML5 doesn't replace Flash for those arenas. It's blatant ignorance for individuals to even come out and claim Adobe should set and end of life date for the product. Sure Flash has had some issues, and they came at the expense of FutureWave Software, Macromedia, and Adobe moving faster than anyone in the web industry at the time, with different goals, that just happen to now be of interest to web developers at large.
The reality is that web tech has just eaten into and provided standardized variants of features that Flash/Shockwave has had for over TWO decades. Yeah, real progressive of the web community. _Slow clap._