I believe it's a combination of a lack of customers and lack of infrastructure. It's a big continent to cover with the necessary fibre capacity, and the market is much smaller for nearby services.

Also what you don't see in things like this, or even a list of datacenter locations, is the relative sizes of the datacenters. After US east/west coasts and Europe, datacenter capacity rapidly tails off. Parts of Asia have plenty but not on the same scale I believe (although I don't know about the Chinese market). The difference in size can be quite a few orders of magnitude between different regions.

Smaller market, less reliable power grids, more challenging heat management, less political stability in many african countries. Also, given their pricing, big cloud vendors AWS are a luxury many local businesses would probably not even consider.

This isn’t just an issue for cloud providers. It’s also not easy to find collocation space either.

My best guess is that it is a combination lower demand (vs rest of world), and infrastructure availability (connectivity + power).

I can imagine a bunch of secondary factors too, but this to me sounds like the key broad reasons.