[TeMPOraL]

> Webpages can still do as they like. That’s general purpose!

That's general-purpose for the third party. Not for the user! This is the whole thing the "war on general-purpose computing" is about - whether the software serves the user, or whether it serves its creator and third parties it trusts.

> let the browser catch up to already do what these extensions want in a more secure way. What’s wrong with that?

There's nothing wrong with that per se. I have the problem with the part involving removing user's ability to arbitrarily alter the behavior of a website.