What happens if some local infrastructure breaks down in a way that that the local community is put to a standstill until things get fixed?
In a non-networked world, the problem is limited to the local community. In a networked world, everyone is harmed.
It's pretty easy to see that there are tradeoffs to be made between reliability and efficiency. As we become dependent on products which are centrally produced (very efficiently) and widely distributed, we all become vulnerable when a disaster strikes the producers.
I personally believe that the efficiency gains outweigh the reliability losses, but that doesn't mean the tradeoffs don't exist.