To contribute something tangible, I've thought on this topic sometimes and I've tried to come up with non-genetic factors such as heat or domestication or disease. But each of these elements is present in areas of the world that did 'make it'. There are plenty of impressive ancient civilizations occupying the blistering tropics that have as many or few domesticated animals as SS-Africa and are also rife with mosquitoes and such. It never stopped them
SS-Africans are the oldest peoples. SS Africa has as many resources as every other continent. All things being equal they should have industrialized first. They did not. Perhaps it is precisely because the distant ancestors of the rest of us mongrelized with Neanderthals and other close relatives that they came out ahead of the purer SS-Africans. Hybrid Vigour is a thing, after all.
Well one of the big things is the climate and the location. You might go 'but egypt' - Egypt is in one of the most reliable floodplains on the planet, the floods of the nile were super regular and helped immensely.
The Congo river is another major river system. Why didn't it get a huge unified civilization like Egypt?
Well, for starters, the Congo is a bitch of a river. It's hard to travel it, it has rapids and cataracts all over the place, its floods aren't super regular, and it's very remote - it's hard to get to the Congo from Europe or the middle east - trade to the Congo would take an immense amount of time, and ancient ship building could only take you so far. The Sahara is an immense natural barrier to cross, and going around it to reach West and South Africa is not easy. What fueled a lot of Mediterranean civilization was the sea and trade along the sea or other routes. Waterways are natural highways for trade, and Africa was involved with quite a bit of trade - in east Africa that is. Ethiopia was a major player in world trade for a very long time, sitting close to the Red Sea and a natural hub for traders trying to get deeper into africa for ivory, gold, furs, etc. Trade creates a feedback accelerating loop. Every new thing you get speeds up your development if you can use it and if you're close to someone else you trade your stuff and ideas they might like (such as the wheel) and the pace accelerates over time. A lot of Africa was not in contact with the rest of the world, or another big solid hub of settled civilization like China, India, Europe, the Middle East. Sub Saharan africa was geographically a nightmare to reach compared to almost everywhere else on the Eurasian/African supercontinent. You had to sail, or cross one of the worlds largest deserts - or traverse some of the most intense brush on the planet.
Africa also has a rain problem. Every other continent has a big, large mountain range which casts rain shadows and helps regulate the general distribution of rainfall. Africa... doesn't really have that. Agriculture without steady rain fall or regular flooding is not easy to sustain on a large scale prior to modern irrigation and industrialized farming. Without reliable, large scale, organized agriculture, you don't get the luxury of being able to have super hyper specialized members of your society early on - you know, like engineers, or scribes. Subsaharan Africa didn't really pick up writing until later on, as they never needed to pick up writing. Without a huge hyperspecialized hierarchical society that needs to keep lots of records of what goes where and what resources to distribute, writing doesn't really develop. You have to rely on oral tradition - and bad luck in one generation can have some cascading effects.
That said, African metalsmiths were absolutely fantastic at their job, especially their iron smiths. There's traditional African forge furnaces that can reach temperatures well outside the reach of the rest of the world until the 1800's, and what they could make with those is just pure art really. Metal tools are all over Africa, same with jewelry, accessories, etc. etc.
About the whole beasts of burden thing, couldn't they just have imported them? Like the last two millenia nobody traveled from the middle east of Africa and told them about the advantages of mutton? Also fix me if I'm wrong, but isn't the ground if Africa fit for agricultural development? Shouldn't have that become the norm rather than hunting?
It is and it isn't. There's plenty of spaces once cleared that were pretty suitable, but people worked much of those, and large scale land clearing efforts were slowed down by the simple lack of need for more farmland in many places - the population isn't high enough for it, or what they've got already is working fine on sustaining them. There's also some
diseases which do a real number on lots of animals, and people infected by it. Animals not native to the area get hit the hardest by it. And by hard, I mean 'are going to fucking die'. So importing animals wasn't always an option.
"What about domestication?"
Good luck. It was really random chance that got us horse domestication - wild stallions and mares will bite and kick and happily kill people - zebras are smaller, just as aggressive, and not the best pack or labor animals. Of the animals in Sub Saharan Africa suitable for domestication, the only one is really the African elephant - but as it's big, the males are very aggressive, and also move in large herds, this isn't easy. And good fucking luck taming a cape buffalo or a hippo.
Also, agriculture was very, very widespread in Africa. It's just as I mentioned before, the climate and geography of sub saharan africa really doesn't allow the super intense farming on one plot of land you got elsewhere. You had to move around occasionally, simply to follow where you could actually grow your crops as the rain patterns shifted. Herding lifestyles were not uncommon either, but by no means was that the default for every community in Africa.
