Well, am not exactly from Nigeria, but let me weigh in here since I work in the same space.
We have to understand the fact that the internet is borderless. The cloud truly is some arbitrary digital location which houses and serves data to anybody with an internet connection. It therefore doesn’t matter to the end-user where the actual physical servers are located as long as they have [high-speed] internet connection.
Even though websites were actually hosted in respective African countries, it would make very little economic sense. The west has access to incredibly power and bandwidth that service providers in Africa have to part with an arm and a leg.
Secondly even for argument’s sake, if we assume websites were hosted in respective African countries, there would not benefit from what would have been less latency(the delay before a transfer of data begins following an instruction for its transfer.). That’s because most telecoms and ISPs in Africa don’t peer traffic between themselves. So even if a website was hosted locally, a user in say Uganda where I come from, would have to go through international gateways (Europe, America) before packets arrive at server hosted in Uganda. In fact, it might even turn out be slower hosting a website locally because of this lack of local traffic routing/peering. As a result, end-users who are browsing don’t even save on data since local traffic is treated at international traffic! There’s no incentive to the service providers, no benefit to end-users and clients to locally host their websites.
If local hosting has to succeed, then African countries have to build local clouds, or regional internets. They have to make internet bandwidth cheap and electricity dirty cheap (just like coal is in the west). They have to slash on taxes imposed on imports of computers, servers and network gear so that service providers can build local data centers cheaply. ISP have to start peering internet traffic between themselves via regional Internet Exchange Points so that local traffic is routed locally and only international traffic goes through the sea cables. In fact users should be made to pay much much less for local traffic than international traffic. This will mean two things; faster access to local content for end-users and savings on data. Hence users will end up preferring to visit local websites than international ones. Then companies will find it more attractive to host their websites locally rather than somewhere in Texas, London or Tokyo.
If the above conditions don’t happen, am afraid, Africans will continue to host their websites offshores because it’s much cheaper, reliable and faster to do so.