>>fidotr+G8
When Microsoft did this with IE, they did it with proprietary and undocumented APIs. The fact that this is an open spec, discussed in an open forum, using well established and standard technologies is what ensures it can never be positioned against users in any meaningful way.
To me it looks like SGX for the web. Maybe it will introduce some neat and weird capabilities, but at the end of the day, it will be trivial to bypass at scale if it ever positions itself as being harmful to users.