>That’s just not an option for a regular phone or laptop, which is most of Apple’s market.

Lots of Macs have more than one video card. I disagree, I mentioned it since they make their own silicon, and can do virtual GPU, memory management for the browser would be an issue, but Apple doesn't care, they just use swap on the SSD and it would still be cool to have that as an option for single tabs. All web browsing is just a huge amount of javascript virtual machines, and they have custom hardware to run it faster, they might do it via hardware, all their sandboxing is just OS based, TouchID ran its own OS and took years to crack, and needs hardware tools to do so.