There is definitely no straight forward answer. I agree, there were many different factors involved. The bottom line is that the Europeans made good use of and developed the knowledge that was available at the time, and the resources which they acquired from colonizing the world. It was brutal - savage even -but they were looking out for their own best interests. Hopefully we would've done the same if the roles were reversed.
Too many people of African descent dwell too much on the history of slavery as if it's what defines Africans. I understand the necessity of knowing history in order to understand the current condition of your people. But dwelling too much on this also creates a victim/loser mentality. Some Africans miss no opportunity to bring up this part of history. It's as if they're hoping to shame and guilt trip the white man into giving up his power and privileges.
History is not over yet, so there's no reason why Africans and other civilizations cannot become even more advanced than the Europeans (who are on a decline) if the right opportunity arises sometime in the future. Too many people have passively accepted that triumphalist European "end of history" rhetoric. History fluctuates and conditions change over time, sometimes very drastically. At the height of pax Romana, nobody could've imagined what was to come a mere few centuries later.
/Rant