There’s been some controversy over presenting politically correct versions of European history. The other problem or rather the biggest problem is that African history outside of Egypt isn’t well known. Some of those African empires may even be Muslim like in Mali and Morocco whilst others like the Ashanti empire (precursor to both Ghana and Ivory Coast) and the Grassfield kingdoms are subjected to some degree of colonialism.
There’s one historically Christian African empire known as the Abyssinian empire (precursor to Eritrea and Ethiopia) but that too is subjected to a degree of Italian colonialism especially in WWII as I can remember. Almost as if the entire history of Sub-Saharan Africa to everybody else is viewed through the Slave Trade.
Though that’s also true, it also obscures the actual histories of these kingdoms and empires that are precursors to contemporary nation-states and regions. Modern day Cameroon is based on what’s left of the Muslim Hausa empire and Grassfield kingdoms as well as Fang kingdoms at that as both Cameroon and its neighbour Gabon have many of the latter. Nigeria itself is based on both Hausa empires and Yoruba and Igbo kingdoms.
Morocco, Libya, Tunisia, Algeria and Niger (practically almost any country with a substantial Berber population) were based on Berber kingdoms and dynasties. The Democratic Republic of Congo, Angola and Zambia are successors to the Kingdom of Congo. Even Egypt itself housed different kingdoms including that of the Nubians and historically included both Sudan and South Sudan.
Not necessarily entirely forgotten but obscure enough to be practically glossed over. It’s not people’s fault for why they think a lot about Egypt when it comes to African history because it’s the most famous. Indeed it houses the Nubians, who are related to Ethiopians if I recall going to Billy Gamba’s blog before. They could simply be ignorant of all the other African kingdoms and empires.