So… you'd rather carry around a briefcase with an attached external handset as a cellphone, rather than a somewhat modern cellphone? What about carrying around a laptop with a tethered cellphone vs. a smartphone? If you prefer the latter options, as many do, then I really do believe that's a solid signal that form is function.
If I'm arguing a straw man, you're arguing a red herring. There is no "RDF" at play here. Form absolutely does impact function. In fact, form distinctly defines function.
