I think a few comparable development tools have sprung up, including ours, Construct [1], which is very much web-first.
I think the reason people say nothing replaced Flash is because now there are lots of tools instead of just one, as anyone can target HTML5, so the market has fragmented; and the market has changed, as people develop for app stores and platforms like Steam, so the web isn't as big a focus as it used to be (although it's still important).