To be fair, I live a bit in the future. I build apps for tech people who are running up to date browsers, and that don't face the consuming billions. On top of that, Polymer polyfills webcomponents and two-way databinding of templates.
Perhaps my apps haven't gotten big enough to see this binding in global thing fail, but I'm not sure how it would ever. You properly namespace everything right?
It simply is not a long term viable strategy, we've been there, we've done that, it does not work. Perhaps that's not what you mean.
Also plain javascript doesn't have observables in most browsers, and any SPA without an observable system can only reach a certain level of complexity.
TBH, what you write is still so far from reality, that plain javascript is enough, that I am a little hesitant to take your comment seriously.