Yeah lets all just use bash commands to browse the web, way more secure and sure you can get the information you need... oh wait wasn't that 20 years ago?
And it would still be possible if web standards didn't accrue so many capabilities that allowed people to treat them as a new medium of publishing color magazines (with invasive tracking as a cherry on the cake).
Not really, not if you think about it. Webmail doesn't need anything more than html(<5)+css.
> online trading platforms
Ditto.
> online games
Honestly, I think running webgames in a super-sandboxed flash (or similar) runtime is the best thing to do. Again, no use for js on the web.