It is. The size and terrain too. It depends on what we’re comparing it too as this question feels like it’s comparing it to the US and Europe. Europe even with Russia is about 1/3 of the size of Africa on a good day. You can’t compare it to Australia and the Americas because they’re colonial states, completely taken over by their colonizers or basically Europe 2.0. Asia isn’t as developed as it seems, people are looking at a few choice powers but not looking at the entire lot and Asia had the advantage of time, trade and water that the Africans didn’t. They also had education. So it’s a complicated question to answer when you notice a few details. Another thing too is that Europe had no outside threat from the other continents due to having nothing of interest to the others, Europeans have a long history of traveling out instead because of it. All those factors played to ultimately work in Europe’s favor but not really anywhere else. It’s like comparing apples to oranges.