..Unless, we can find a way to have post quantum protection without further increasing key sizes to afford the security.

Even then, it's a big stretch unless a) everyone that uses this has access to many GB's of bandwidth or b) we find some way to keep consensus without using present fios/network infrastructure for io into the blockchain.

Perhaps, if quantum computing were achieved, then this would be a possibility. Where the problem we were to solve presents a solution that was previously unsolvable.

http://www.theguardian.com/science/2014/dec/15/secure-quantum-internet-photons-computers

So, really all we gotta do is focus on quantum secure algorithms and the rest will take care of itself, space and network saturation be damned.

There's your niche.

Dream big or go home boys