They tried. The V8 team eventually gave up and said it was unwinnable.

What they did do is move tabs to their own process so they can take average of the operating systems protections. Yes you can read the memory of the process hosting the JavaScript, but now there isn't anything interesting in it. Google's security team released a proof of concept attack that can read the memory in the renderer in many systems.

average -> advantage

Man mobile keyboards suck. Any idiot knows the word average doesn't work there (at minimum you'd have to preface it with the word "the"), so why can't my keyboard run an ML model that's not an idiot?

Didn't even notice until reading this comment! I think my brain said, "starts with an A, got a V near the beginning, ends in AGE, must be ADVANTAGE in this context."