I think the key to Africa is the same as the key to India. The conflagration of languages other than English or other than the majority. Africa still has a diverse language stack that stifles its progress. 2000 languages. India had ~750 languages 50 years ago. Today it has ~250 languages.
which is very relevant to SMEs, the driving force for about 98%+ of economic activity, jobs, tax revenues etc and the economic progress to increase the standard of life, you don't really see language as a variable. (and it's a pretty comprehensive report).
I mean, how bad is it, really? Most countries have multiple languages, but also a single official language. I've been to Africa many times and due to its colonial history French, English, Spanish, Portuguese, they get you pretty far in most places. In my own city we have over 175 nationalities, but communication is never a problem. It would be a mistake for an outsider who never visited to look at that number and then claim it's the origin of any particular problem in the city without any extra information. So I'm genuinely interested if you know of any studies that show the language diversity is a stifling issue.