Can you confirm for me what you think a proposal is?
It has been my understanding that the w3c doesn't make those internally, the community does. It just so happens in this case that some of the proposals came from the Chrome team at Google which had been spending a lot of time with devs and found some valuable additions to be made to the platform. In that case of Template Instantiation it comes predominately from Apple. In the case of HTML Modules, Microsoft.
Is the w3c not a consortium on many vested parties that together come up with the future of the web? You speak as the web we all work with is laid down as dogma from some shadow group.
Are you seriously suggesting browsers shouldn't focus on implementing anything and everything that is being massively polyfilled in the wild?
When you understand that the w3c's protocols on creating and establishing those standards would always start with a proposal that would need data (like how many like this implementation and how many people/devs/companies are implementing this proposed spec) to back up the claim that this spec is the way forward... then you'll understand that the web standard will always start at these proposals.
Besides, these proposals has phases.
"Browsers should implement what w3c envisions..." <- I think what w3c envisions always start in those proposals... and technically, they are already doing it.
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