I live in Tanzania :)
I think you're overestimating the impact of bitcoin on poor countries by several orders of magnitude. People who don't have access to a bank account now don't have a smartphone, and certainly not a computer either. And internet access is rare and expensive (most people have dumb phones, internet at home is a rarity, and most coffee places charge you for wifi).
On top of that the only way to buy bitcoin here (for now, at least) is to send money through western union to some guy on localbitcoins and of course, that's far from "almost zero cost" or "without a middleman".
I'm not trying to rain on your parade, but the reality is that it's still much, much easier and cheaper to get a bank account than bitcoin here (you can open a bank account in less than an hour, with a minimal deposit of 50$. That allows you to use ATMs and send money anywhere).
So I come back to my original point, adoption is margnial, at best. Especially in poor countries.