> Providing full read/write access to all websites is a huge security risk, and the fact that we're willing to do it is really a testament to how bad the state of the web is without adblockers.

That seems to be completely ignoring that extensions aren't just independent self-contained programs. They're intended to extend and modify the capabilities of your user agent to better suit the needs of the user. Trusting the user agent with full read/write access to the data it's fetching is fundamental to the purpose of a user agent. Sure, it's nice when you can sandbox a helper, but it's irresponsible to suggest there's anything wrong or unusual about having the kind of powerful extensions that Google doesn't want you to have.