I'd really love some visibility on this question; I've seen similar questions on this subreddit but they all have low visibility and answers without satisfying depth.
I saw it proposed in some reddit comment elsewhere that two things are needed for advancement in a region: that the land must be defend-able, and it must be fertile. The commentor suggested that Africa's struggle to keep up with the rest of the world is due to all regions except the Nile lacking either defensability, or fertility. Is this a valid reason from a historical perspective?
Sorry for the double question, there just seems to be so little un-politicized discussion on the subject, and I'm starved for credible insight.
There've been so many comprehensive posts on this topic I don't even know where to begin. You'll probably enjoy these ones by /u/commustar:
Why did civilization develop in southern Mesoamerica but not equatorial Africa?
How were Central and Southern African civilizations during the Ancient Era?
Why did the Romans not annex or set up a client kingdom in Ethiopia?
How valuable overall is the distinction between North Africa and sub Saharan Africa
What was going on in what is now Sudan in Ancient and Medieval times? (with /u/cleopatra_philopater)
Why is Africa not as developed? by /u/khosikulu
To what extent were the Romans in contact with native African tribes? How deeply did Rome explore, but not necessarily conquer or colonize, the African continent? by /u/cleopatra_philopater
The native americans and several other cultures did not experience the same technological advancements as europe. What has caused this diffrence? by a now deleted user
What happened to Africa's ancient empires?
And then there's the FAQ on why Africa is seen as less developed by laypeople
The FAQ on Technology and Civilization in the Americas
If you're not averse to reading I recommend checking out the recommendations in these posts.