A Western/Technology View
So this is a survey by an organisation in a developed country advocating that less developed countries have to spend money on tech.
Voice calls are a very good communications tool and can be beneficial. The trouble is that for rich countries the voice function of a phone is barely relevant, it is everything else that does the damage, destroys cultures and socienties.
Being a "developed" country is a uniquely Western philosophy where countries that don't have access to what we perceive as critical services as being deprived.
Providing clean drinking water, sanitation and education is probably a better use of money than this. Yes is has its place, but just not how the west perceive it.
Biting the hand that feeds IT
