Not sure I follow the first part of what you're saying.

For the part where you're describing what's possible or not in TypeScript/JS, though, you're incorrect:

You can't do something like title("hi") vs title({attr:123}, "hi")

Yes, you can. In JS it's trivial; in TypeScript, you can even do it while preserving type safety. Here's the function in TypeScript:

    // First define which signatures are allowed
    function title(content: string): string;
    function title(attrs: Record<string, any>, content: string): string;

    // Then, implement the function, handling the two possible cases:
    function(contentOrAttrs: string | Record<string, any>, maybeContent?: string) {
      const content = typeof contentOrAttrs === "string" ? contentOrAttrs : maybeContent!;
      const attrs = typeof contentOrAttrs === "string" ? {} : contentOrAttrs;

      // now use content and attrs as you please
    }

This will be typechecked by the compiler so that if you call title("hi"), it'll know there are no more arguments, and if you call title({ attr: 123 }, "hi"), it'll validate that the first argument is a Record<string, any> and the second argument is a string.