Well, it can be useful to represent your app as an npm package since it allows easy deployment in node.js environments. Besides, if your app needs server-side logic, the node.js ecosystem provides a lot of options in this area.
However, if you have a pure client-side application, it’s absolutely valid to just use a service for serving static web content (which is not necessarily based on node.js). It seems the discussion of your other topic Still trying to persuade Chrome to be hospitable with my apps goes in the same direction.