Ryan Dahl describes the JavaScript sandbox as a higher level container for server software:

This container isn’t meant to address the same breadth of problems that Linux containers target. Its emergence is a result of its simplicity. It minimizes the boilerplate for web service business logic. It shares concepts with the browser and reduces the concepts that the programmer needs to know.

People like Ryan and his colleagues at Deno are exploring this future, but it’s not quite here yet.