Then again, what do you expect of countries where small groups of elites monopolize the economy?
As an ordinary Senegalese/Ivorian etc with some money ... go try and file for a mining license in your country.
Unless you're part of the ruling clique they'll laugh you out the building.
Its the same for most of the primary sector... even commercial agriculture.
Without access to the primary sector; domestic value generation would depend on unqualified people who got there through nepotism & etc.
If the primary sector is out of the picture then the sectors above it would be non existent.
Iron mining > transportation > metal refining > machining > end products manufacturing > sales & marketing & etc
Just the mining industry alone could open up dozens of industries higher up in the value chain and employ millions.
However, other than to friends or foreign companies, African governments aren't too keen to open this up to their citizens.
Mainly, because any rich people outside of their network would be seen as a threat to them.
I'm sure if someone did some research into this they would hardly find any independently rich Africans that gained their wealth in Africa.
Here's some old data to make it painfully obvious:
Keep in mind that only 25% of the rich in Africa are based in Sub sahara Africa (excl S. Africa) or less than 1% of the population of the global rich.
Don't African countries calculate the informal sector in their national accounts documents and hence as part of their GDP?