We had decentralized web standards in the past, with browser vendors implementing new markup features on their (and, to a lesser extent, their users') whims rather than marching in lockstep with some "central governance" - the First Browser War, where Microsoft and Netscape were slinging it out for market dominance, adding new features as quickly as possible to gain more users and simultaneously create a captive market by way of incompatible markup. Yes, this gave us Javascript (if I understand my history correctly), but it also gave us such abominations as the "marquee" and "blink" tags, and no one who worked through those times as a web developer looks back on them fondly.

I am not saying the current situation is ideal, but it is better by leaps and bounds than what it used to be, and what you are proposing.