@alwayscurious @swordgeek @theearthisapringle I don't really see it as a "sadly". The norm is that applications working with complex data from different privilege domains should run in different execution privilege domains.
Browsers just kinda evolved from simple low attack surface document readers to application platforms, and at the same time political norms against malicious behavior disappeared.
But in what they are now, it absolutely makes sense to put them in their own execution privilege domains. Not the fake way FF & Chrome do where there's still shared context with all the secrets in it. But entirely isolated.