Anything that could be done to make a separate application space run safely could be done to make them run safely on the existing web, couldn't it? Yes, but yo

Anything that could be done to make a separate application space run safely could be done to make them run safely on the existing web, couldn't it? Yes, but you could tighten things down and treat the modern web as a transient application delivery system. Where users have to explicitly grant access to each application, and grant it whichever specific permissions it needs. I also wouldn't be against having two browsers, one for running applications and one to browse the web.