Imagine someone writing a whole app like this

worst-idea-ever.js

function subtract({ [subtract.minuend]: minuend, [subtract.subtrahend]: subtrahend }) {
    return {
      [subtract.difference]: minuend - subtrahend
    };
}

subtract.minuend = Symbol('subtract.minuend');
subtract.subtrahend = Symbol('subtract.subtrahend');
subtract.difference = Symbol('subtract.difference');

subtract({
  [subtract.minuend]: 10,
  [subtract.subtrahend]: 7,
})[subtract.difference]; // => 3

// Now imagine there's a huge object passed around with params to every possible function...

Actually I love the idea of returning objects for each calls.

Pros:
➕ Every parameter's name is visible in function calls.
➕ Multiple results are trivial (the choice between array/object/closure/global map key is always in favor of object).
➕ Result value is coupled with its intended semantic. If we're using symbols, the coupling can be as unambiguous as it can get.
➕ Go-style error checking¹ for free: just return truthy value in "error" property (or even Symbol.for('error'), App.symbol.error, App.instance.getErrorSymbolForNamespace(...) if you're into that sort of things).
➕ Returned objects can be proxies, which I imagine could be useful for lazy computations and all sorts of smart h4xx to solve business problems in complex domains in a lean and efficient way.

Cons:
➖ Verbose.
➖ Feels wrong.
➖ Possible performance overhead. Though from what I know V8 is good at optimizing that, so this warrants further investigation.
➖ If you want strong typing, you know where to get one.

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¹ Yes, I hate JS exceptions. No, I don't just hate exceptions in general: e.g. I enjoy how Swift does them.