Sure, Africa is the poorest of all the continents. Without a doubt. They lag behind for a variety of reasons. But times are changing. "Food aid" is not helping them develop their agriculture and perhaps when big Agribusinesses invest more, productivity will increase. But "free" will kill any market anywhere.
"6 Largest Shopping Malls in Africa"
Source: https://seeafricatoday.com/travel-guides/shopping-malls-in-africa/
"These cities are the hubs of Africa's economic boom"
Source: https://bigthink.com/strange-maps/richest-cities-in-africa/
I found the article with URL below most interesting, because we shopped open air farmers markets in Germany every week, and now here in the states we still buy from some farms, including having picked tomatoes and okra and sweet corn last week. So, there's that.
"Persistence of open-air markets in the food systems of Africa's secondary cities"
Source: https://www.sciencedirect.com/science/article/pii/S0264275122000476
As you observe "African poor is exotic and “rust belt”/Appalachia poor is beneath notice." Wish it all weren't.
We patronized in Germany and still patronize here open air markets and local farms because we want them to have enough business to prosper. It has the additional feature of side-stepping multi-national Ag. Yeah, we bake our own bread too.
Agriculture is no longer labor intensive, as it was in the past. The West continues send Africa their second-hand clothes. We are trying to help them. But we are hurtingthe developmentof their economies when we are doing it.
Reality Check: Why some African countries don't want charity clothes