Five years is nowhere near long enough for the entire platform to be replaced with something completely different. Unless, of course, you mean the "OS" and VM that is already in our browsers; but it seems apparent you don't want that OS and VM, you seem to want something very, very different (and different in ways that nobody is really working on, as far as I know).

I'm less critical of JavaScript, but I've also got a much more conservative expectation of how much will change in any five year period. Your estimate assumes more dramatic and rapid change to the web than at any point in its history (except maybe the initial introduction of the graphical browser, or of the release of JavaScript, itself), and an ecosystem with a few billion participants does not and cannot change as fast as one with a few thousand. And, of course, for something to be the way we all do things in five years, somebody would have to be doing it that way today on a small scale.

Please don't kill yourself, despite the fact that your dream definitely is not going to happen the way you've envisioned it. (In its place will be a gradual, but measurable, improvement on nearly every front in the systems we currently work with. It'll probably all turn out alright.)