How long do you think it will take Africa to fix bad network?
Anyway, bitcoin adoption isn't very close to many continent for now, not only Africa.
I think it's easier to convert btc to usdt (for example) by sitting at home than trying to convert your local currency to more stable or vice versa. Local exchanges offer not a good rate at all and governments prohibit exchange of currencies. Crypto could give people the opportunity to have control over their money and become independent from local currencies fluctuations.