Networks are certainly not unreliable people are, with advanced
protocols which multi billion pound companys depend on for transactions
and the functioning of their business they have reached a brilliantly
reliable stage.
Ie, STP, and tonnes or routing protocols such as BGP, IS-IS, OSPF, they
permit private networks to adapt and work even when half the earth is
missing! The internet is only unreliable due to the static routes that
ISPs program into their routers which dont evolve to the dynamic
network.
With evolving technologies such as biological computers using neurons
(just google it), and I heard somewhere they were creating monitors
using similar techniques.
But no system is perfect and any system can be knocked en masse out
using various methods, huge companies and the goverment just keep them
underground in nuclear bunkers anyway