One of the disease eating up Africa's development was the brainwashed the European slave masters gave to them about school. They were taught how to read and write what the Europeans wrote,no skills attached,no knowledge just know how to read and write. Today, the world has gone beyond you just acquiring degrees to you acquiring skills and knowledge. The world economy is been revolutionized and Africa lacks the man power to do that . Africans just attend universities to learn more than what they learnt in primary and secondary schools.
I think your conclusion based on phenomenon faced by many African and developing countries such as high unemployment rate, many graduates fiddicult find suitable job related with their study, only primary sector developing where middle and advanced industries still lagging behind which cause economy dependence on primary sector which mean no njeed high qualified skilled people. This condition bring brain drain due to limited opportunity, this is exacarbated by mismatch between available study with job market/ mot aliged with industry need, and no place fotr practical. All the condition bring people conclusion (including OP) that education is useless, school only create individuals who are academically intelligent but lack practical experience.
Based on my experiences in my country paper degree and certification not only a sheet of paper, although certification does not guarantee our quality, but it is a proove that ensuring we have gone through the education process and met certain competency standards. Beside that, some of profession cannot be executed by independent learning. Reading and writing are foundation of knowledge, without it world will face generational degradation, and nowdays we have found many of these degradation problem in our kids.
Just try to imagine, engineering, programmmer, researcher or entrepreneur without literacy, they will not have ability to understand information, analysing data and continue learning. Africa may also lack educators who can package and serve knowledge in a delicious way, which will make student are enthusiast to consume knowledge.