I would hesitate to say that the GAFA will never see full mobile reception, but I also seriously doubt that it will happen for a long time yet. In maybe 40 or so years time...
We will see it eventually, but only when your average mobile phone has the ability to roam on some kind of satellite service (Inmarsat/Iridium etc).
We will never see a terrestrial mobile network cover these areas. Imagine the cost of installing and nightmare of getting power to thousands of remote sites that have zero daily users just in case the occasional douchebag gets stuck without appropriate survival equipment and preparation. Not going to happen.