I am not so sure it is physics but accidents of economics business and Engineering. Companies have not been so enthusiastic to put optic fiber to where people live. Also the TCP protocol doesn't support really fast connection when you're going up to a gigabit or so. There is a company with a patented protocol based on UDP that companies like Disney use to move big video files around.
I believe you're talking about Aspera, recently bought by IBM. It's pretty fast and reliable and I've never had a problem with it over even residential Internet speeds ( many master files for delivery well over 100GB). Bitmax is the big CDN that uses it for media delivery.
There's a free alternative I have to talk up any time Aspera gets mentioned, and that's GridFTP by way of Globus Connect.[1] It's pitched as a way to move massive quantities of research data around, but it's free for personal/academic use and dead simple to set up.
There's a standalone command line client too [2], but it requires a bit more knowledge of how to tweak the settings, while Aspera and the Globus client does a lot of auto ranging stuff.
In any case, both of them will easily get you line speed from your slowest node.
As fibre optics develops, so do storage device densities, though. You can now get a 3.5" drive with 8TBs, which would take 2+ hours to transmit at 1Gbps, even assuming perfect bandwidth utilization.
