It's hard to imagine that 2.9 billion have no access. In the 2000s Ethiopia had the most robust cellular network in Africa despite having no government. The reason was because of the lack of government banks couldn't really operate, but cellular companies physical infrastructure only really depended on cell towers. Cellular providers could be the middle men in international wire transfers. All you had to do was send a text and your cellular company could effectively become your bank.

In places with the least infrastructure it seemed there was the greatest incentive to provide the latest technology.