Well, the browser already uses the GPU to render. The difference is how you manage state. A lot of web applications do that in a slow way by storing data in the DOM for example, or do things that require the browser to re-render the whole scene.
You could port FB to Canvas and it'd probably be faster until you add a ton of abstraction to give you what HTML does.
You could port FB to Canvas and it'd probably be faster until you add a ton of abstraction to give you what HTML does.