There are many countries in Africa in which there are no centralized fiat exchanges.

The central banks in many countries (e.g., Kenya, Tanzania, Nigeria, and more) simply prohibit the domestic banking networks from serving not just bitcoin exchanges but companies and individuals engaged in transacting with, or trading in, bitcoin. And international wire transfers to and from foreign exchanges are rejected by the banks of these countries, so even though an exchange like BitSTAMP will allow users from a certain African country, there's no opportunity for a user to use their bank to move funds into (or out of) those exchanges.

Bitcoin Exchange Methods In Africa https://kenyacoin.medium.com/bitcoin-exchange-methods-in-africa-39ec3bbb859b

Of course, these restrictions impact everyone except the elite -- who can buy and sell bitcoin using their offshore accounts, without interference.