We should simply start doing new standards through other organizations. There's no fundamental reason to float new standards through W3C rather than some other organization.
You are of course right that browser developers/vendors get to decide what they're implementing. But web authors, OTOH, can decide which format their works are published in. Browser vendors and WHATWG have shown no interest in simplifying the web. Rather, they're piling up monstrosities of unnecessary complexity, with the effect that, willingly or not, it is becoming infeasible to develop a new browser from scratch.
Most of all, WHATWG seem uncapable to come up with any privacy protection mechanism; instead, we're getting DRM. Honi soit qui mal y pense