I looked up this video because...wow...what a bold and untrue statement. I want to preface this by saying that the focus of this answer will be on Britain, which was the most "successful" empire in Africa during this period, and I am most familiar with this narrative. Next, before moving on, I want to point to his two "best" sources for this section of the video are John Gunther's inside Africa and Douglas Porch's History of Colonial Wars. The latter is a military history that is under 200 pages and focuses on military matters, although it does lay out the economic drive for imperial conquest of Africa. The first book, on the other hand, looks to be somewhat interesting and certainly more relevant. It is written by an American Journalist that traveled throughout African and conducted many interviews. But reliance on this text ignores some obvious pitfalls. First, Gunther did not know any African Languages as best as I can tell, and he experienced Africa in the post-war era, after the the high point of colonial exploitation. And i think here this WIAT fellow misses a major point, and suggests to me that he had trouble seeing the big picture when making this video. He states that there was something like 10000 colonial officials in Africa in the 1950s. This is hardly a metric worth considering when evaluating the extent of colonial exploitation in the 19th century. Most of the western European countries were flat broke after World War II. Both world wars devastated the continent and would have not only completely destroyed these countries' ability to maintain a significant colonial apparatus, it also sapped any willingness from many of the inhabitants of these countries to contribute to such an empire. Tony Judt covers this disillusionment extensively in Postwar. He also discusses the financial situation of these countries, and points out that the French were only able to devote significant pieces of their GDP to fighting the Vietnamese revolutionaries because the Marshall Plan was paying for everything else they needed. To conclude this piece of my answer, we cannot look to 1950s evidence to assess levels of colonial exploitation SEVENTY YEARS EARLIER.

The whole segment on imperialism in Africa in this video suggests an inability to grasp the entire scope and goals of imperialism. This is likely rooted in a couple of factors. First, he is assuming that British and other European investment in their African Empires was low, and therefore they could not have been doing much exploitation and that these governments did not generate revenue via their colonies. Let me address the second of these misconceptions first. This video misses the point that the drive for colonization came from finance capital that went hand-in-hand with the state. As Burbank and Cooper write in Empires in World History, (I am summarizing 313-315 for ease), Africans had centuries of experience trading with European (and other global) polities and had developed small states. But this was problematic for the Europeans. Independent states could be unpredictable and could lead to "instability, trade monopolies, and interruptions in the flow of raw materials on which industry and social stability at home depended." So as European technological ascendency increased, it became more feasible for European powers to secure the flow of raw materials. The creator of the video suggests that "low investment" from European states suggests a low level of exploitation, if any. But this misses the point that at least in Britain, chartered companies muddied the water between state and private administration of African colonies (see also Empires in World History as well as Shillington's History of Africa). In fact, SHillington describes this employment of companies to undertake colonization as "investment on the cheap." SHillington states "In theory the company would 'open up' the territory, set up a rudimentary administration, invest in railways and introduce Africans to a cash economy. THis would in due course build up markets for European manufactured goods. But in practice the system was widely open to abuse, mainly because it was motivated purely by short-term private profit [not the state, which is what the video creator assumes colonial exploitation would lead to]. There was little long-term investment in administration, roads, or railways. Instead the companies concentrated upon the violent exploitation [lol] of the people and their natural resources." Investment capital financed quite a bit of this colonization because the returns would be an uninterrupted flow of raw goods. And remember, it was raw goods that Britain wanted. The suggestion that the fact that Europeans did not want to industrialize the continent suggests no exploitation completely misunderstands the goals of European imperialism during this era.

Europeans wanted a source of raw materials that could be finished in Britain, not the colony, and then sold to the colony. So, rubber was stripped from African forests, processed in England and elsewhere in Europe, and then sold back as finished goods to the Africans. Creating actual production in the metropole would completely negate this goal. Finally, Europeans wanted to do this with as little actual investment as possible. In fact, the video's creator points to India as an example of a colony that England was able to exploit because it had already achieved a certain level of development (he never defines this), but England actively sought to deindustrialize the subcontinent. Throughout the period of colonial rule, you see the subcontinent shifting from a net exporter of finished goods to a net exporter of raw goods and importer of finished goods. Colin Simmons addresses the reasons and various causes of this de-industrialization in "De-Industrialization", Industrialization and the Indian Economy, c. 1850-1947. The complicates this trajectory, but the fact remains that according to a table found on page 600 of his article that over the course of British rule, India dropped from being responsible for 24.5 percent of the world's industrial output to 1.7 percent over the course of British rule. This was the whole point of Gandhi's self-reliance movement; but I digress.

Ok, let's talk about exploitation Africa. The creator of the referenced video suggests two reasons to explain why Europe didn't exploit Africa. The low investment from the state and the low levels of social development--there were no African "states" and they had achieved a low level of socioeconomic development. Setting aside the racist and Eurocentric presuppositions of this perspective it completely misses the point of European colonization of Africa.

Let's return to Africa. Africa is an incredibly rich continent and supplied many goods that European markets craved, particularly rubber. Returning to Shillington: "The main object of concessionary exploitation in the tropical forests from the 1890s to the early 1900s was wild rubber. The spread of the bicycle and motor car in Europe and north America stimulated a boom in the world market for rubber which only subsided with the development of plantations in south-east Asia between 1905 and 1910. Company agents took their private armies of African ex-slaves [remember the british state is doing this on the cheap] into the Congo basin and forced the local people to collect rubber from the forest. Shillington goes on to quote a Times Article from 1895 about the congo that is illustrative: "It has reduced the people to a state of utter despair. Each town in the district is forced to bring a certain quantity [of rubber] to the headquarters of the commissaire every Sunday. It is collected by force. The soldiers drive the people into the bush. If they will not go they are shot down and their left hands are cut off and taken as trophies to the commissaire. The soldiers do not care who they shoot down, and they more often shoot poor helpless women and harmless children. These hand, the hands of men, women, and children, are placed in rows before the commissaire, who counts them to see that the soldiers have not wasted cartridges." the cahpter goes on to describe agricultural exploitation in north and west Africa and elsewhere.