Disclaimer: I'm not being racist, nor am I trying to be.
There's no giant African empires, with ruins and legacies, like we see in other parts of the world. In South America we see remnants of the Aztec, Mayan, and Incan civilizations, who built extensive roadways, and impressive cities that are still standing today. All across Europe there's medieval castles, there's empires with legacies like Rome and Greece (who, at one time or another, were extensive/successful/prosperous/influential). In Turkey there was Istanbul/Constantinople, in the middle east there were the Sumerian and Babylonian empires, ancient Egypt (yes it's technically on the continent of Africa, but it's right on the edge and basically part of southern Europe). India had extensive empires, and so did China.
We don't see anything like that in Africa. (I mean technically Egypt, but...) There's no remnants of a prosperous empire, or ancient (or even recent) civilization.
In terms of world powers in the (semi)modern era, we have America, Russia, China, Germany, France, the UK, the EU, maybe India, Japan, Brazil, etc. There's no large, powerful, prosperous, influential African countries really. Maybe South Africa is partially successful, but no countries really look up to them and aspire to be like South Africa, nor are they influential in any real large-scale politics.
Why is that? Was it geographic factors?
There were numerous states and empires in Africa. The Ghana, Mali, and Songhai empires were all large, wealthy, and powerful empires located just across the Sahara from Morocco. The Kingdom of the Kongo in Central Africa, Great Zimbabwe, Mutapa, and the Zulu states in southern Africa were also rather large. Ethiopia has a tradition of urban civilization stretching back to Classical Antiquity, was one of the first kingdoms in the world to adopt Christianity, and successfully resisted European colonization (except a minor occupation by Italy). Somalia had numerous states like Adal which had close contact with the Arabian peninsula. The coast of East Africa was home to many Swahili city-states like Zanzibar which were major participants in the Indian Ocean trade networks. The coast of West Africa also had several kingdoms that were present during the age of colonialism like Ashanti, Benin, Oyo, etc. If you're willing to count North Africa as part of Africa you can add numerous others to the list (including Egypt, Carthage, Morocco, etc.)
These civilizations aren't talked about that much. They're not covered in schools. "World History" courses in Europe and the US are often just "European History" with a dash of Asia. The rest of the world is only covered when Europeans arrive there during the age of colonialism. Popular books and movies on them are also few and far between. Unless you take a college course on sub-Saharan Africa you're rarely exposed to them, which leads people to conclude that there were no African civilizations.
Edit:
The AskHistorians Podcast has an episode on African Urbanism which you may find interesting.