The US infrastructure is partially made of copper. It would be very expensive (but doable) to change that.
Laws, carriers, whatever. Doesn't make a difference, we still have no say over enacting your suggestions. We can sit here and theorize all day about what may work, but if you cannot implement or test your solutions in the real world, what's the point?
That's why I suggested coming up with solutions that do not require the participation of large entities. Although I am HIGHLY biased, since I'm working on a peer to peer solution.