So the issue is not that "more data centers are needed urgently" but rather than the question of why the price situation is the way it is.
The main expenses of a data center (just colocation, not renting VMs) are the capital costs of building/renting the facility (including digging some land to pull fiber etc) and paying staff. It's not obvious to me why in Africa these costs would be higher than in Europe, but apparently there's some reason.
I don't see reliable power as a big differentiator since even in the first world your data center anyway needs backup generators; it's just that they would get used much more often.
I don't see expensive bandwidth as a big differentiator since (as far as I understand) the big bottleneck is the undersea cables, and hosting your data on the "wrong side" of these cables should be more expensive - ISPs (at least elsewhere) prefer to cache/re-host/CDN popular data locally as some extra servers in ISPs datacenter turn out to be cheaper than hardware needed for all the extra traffic.