Why we did not develop our own technology in Africa despite seeing it from other peoples is because in sub-Saharan Africa we rejected a lot of developments due to simple complacency among other things. We almost didn't believe anything was greater than our way of life. Some African nations called the gun, the "coward's weapon" just to show how disdainful Africans were of Western technology. So even if we did see many modern technologies on journeys & from colonisers, we didn't think that they were better than our way of life on most occasions & technologies we saw as better or superior, we - obviously - quickly adopted. This was the southeast African mentality.
I can quote two lectures online of people more educated than myself on why Africa didn't develop the same technologies that Eurasia managed to develop, one cites simple geography & the other cites modern misunderstandings of ancient Africa but I'm going to note that culture & the accepted ideas of a given people played a role in many African nations remaining unaccepting of foreign technology. In some regions, colonisers might have caused so much damage that anything they came up with from their clothes, food & technology may have been rejected. It was not lack of intellectual capacity that made Africa lag behind Europe & Asia but more culture, environment & geography coming together to prevent the adoption of new technologies.
The quality of life in Africa correlates with our experiences; Africa is a large, hot, hostile continent... we have the common idea that possessions are not permanent so we often didn't bother in making non-permanent items, especially in southeast Africa. This was the same for Australasians & Native Americans as well. The only reason it seems like the southern African way of life is unique & exotic may be simply due to our skin colour. There is no other way to put it because on other continents they lived lifestyles that focused less on possessions as well. There are "uncontacted tribes" today in modern America & Asia who have not discovered the wheel & might be considered less developed than most African countries.
Despite all this; the destabilisation of our nations, way of life & hostile environments - Africa has made a lot of contributions towards the development of the modern world. Comparing African countries to China by claiming that China was one of the poorest countries in the world thirty years ago works in humiliating Africa. Sure. But putting into context that China's massive population shares one language & national ideal while Africa's nations were forced into ethnic conflicts through European-made national borders & dealt with unfair deals in terms of land & mining since the 1800s will make you understand that China had a sociocultural advantage & was given a further economic advantage when the world (i. e. USA & associates) made China a giant manufacturing plant. There's no reason an African nation focused on agriculture, shelter, industry & defence couldn't be successful even if that African nation never reaches the heights of China & Europe.
Our quality of life in Africa needs to be a priority or we'll forever be just the struggling, malnourished, corrupt Dark Continent. We cannot compare ourselves to other continents when we were clearly dealt a different set of cards.