many people, myself included, view Web Assembly has a future virtual machine that is universally available across hardware, ending the hassle of making specific executables for each operating system. A kind of improved P-Code system, if you are familiar with how UCSD Pascal worked (another brilliant Prof. Wirth project).
That's a very different claim than your parent post.
Portable generic VM (like the jvm but for anything), sure why not.
Having web browsers allow arbitrary access to hard disk? That's something else.