So... I even agree with you that this is true, because exporting cheap raw materials and then buying back a more expensive processed product ends up creating an infinite imbalance and perpetual external dependence... This isn't a problem exclusive to Africa; you find this on several other continents.

But, my friend, I think the problem is much worse than that... it's not just the lack of industrialization, but also the precarious infrastructure, political instability and corruption within a country, the difficulty in obtaining funding for research and development projects for modern solutions, the lack of specialized labor... in short. There are countless barriers to a country's development; it's something that lasts decades, but it needs to start in some way and be continued by future governments.

Othrwise... you can build a bunch of factories in Africa, and they'll still remain trapped in a model of dependence, going bankrupt or being acquired by foreign companies.