I consider any computer platform that cannot run an "untrusted" application in a manner that doesn't endanger its user (within certain limits - e.g. it's practi

I consider any computer platform that cannot run an "untrusted" application in a manner that doesn't endanger its user (within certain limits - e.g. it's practically impossible to limit what kind of internet traffic the application can do, or what kind of scams it can make the user click through), a failed computer platform. In particular, browsers could always run JS in a separate process that's appropriately virtualized (i.e. has limited access to host information and resources).