Why do we allow Google to singlehandedly keep pumping garbage into the web ecosystem? Do they own W3C?
This makes perfect sense if you think about it, because the browser makers ultimately decide what goes into the browser. If the W3C was "in charge" and tried to make Google (or another browser maker) do anything, Google could simply ignore them. That system wouldn't last.
It has to work this way ... and Google (along with Apple, Microsoft, etc.) have decided this syntax is best for them (and possibly their users).
The W3C is descriptive, not prescriptive. It doesn't have any regulatory power, so it can't make design decisions or value judgements of any kind. It isn't even a separate group from the browser vendors; while individuals may join, the vast majority of active members are the developers working on the browsers.
The teeth come from the other browser vendors. They make pledges to each other to implement each other's features. They collaborate through the W3C to come to a consensus on feature designs, because a feature can't get standardized if it's not implemented by more than one vendor and it won't get implemented if the vendors can't come to a consensus.
Anything the W3C says is not how browsers should work, it's how they already work.