HTML5 is the future BECAUSE it is truly multiplatform and that everyone can potentially do an interpreter, an ecosystem ruled by rules so you Can rely on others, instead of reinventing the wheel.
as I said before, browsers are just a partial part of its ecosystem, browsers currently failing never means it is impossible, it just means we have to make them try harder to correct the issues.
bugs have to be corrected, never to be worked around, and html5, css, and JS are part of a specification, not a "browser language", if we cannot make it work somehow, it would simply means that we cannot make an entire ecosystem agree on rules, which is more worrying than anything else.
as for the jerkiness, if they cannot vsync properly, then they will have to do another way.