That's already the way it works in the real world... the standards are irrelevant and ignored, only caniuse and browserslist actually matter. Like it or not, Blink is the new IE6, and its marketshare is only increasing.
Ideally it would be something not controlled by Google but by an independent third party (hand Blink over to Mozilla, deprecate Gecko?), but good luck with that.
Maybe this system wouldn't be as ideologically pure as building compatible renderers to a set standard, but it would result in far better developer and end-user experiences as the web quickly standardizes to a single renderer. The world simply does not need 10 different ways to display HTML with 90% compatibility.