Grass roots wireless mesh networks are a nice concept in theory but no one has ever made them work well at scale. It's just a very challenging technical problem with nodes moving around around, going offline, intermittent radio interference, etc. So the routing tables constantly change. And unless people are willing to buy specialized hardware such as towers and antennas, the range between nodes can't be more than about 100 m.

The One Laptop Per Child project tried to use such a network to serve remote areas but it never really worked.