How is industrialism (specifically economic and social change) addressed in Heart of Darkness?

Industrialism can be defined as "the idea or state of having a country's economy, society, or political system based on industry (see second link below for Cambridge Dictionary). The Industrial Revolution of the eighteenth-century had transformed Europe from a largely agrarian society to an increasingly urban one, with much of the rural population moving to the towns and cities to work in the factories there. The social impact of this change was enormous. The ability to create more, faster, better, and cheaper using machinery made men millionaires in short order, while the ability to make money at such a rate tempted the factory owners to exploit their workers. Heavy industry runs on the labor of the people who power the machines. The faster the machinery can be made to run, the more it can create, and the more profit the industry can turn. This simple calculus led to appalling exploitation of the factory workers, and a concomitant rise in social welfare programs designed to alleviate the workers' suffering. People campaigned vigorously for political changes to limit the abuses inflicted on the workers, and by Conrad's time, there was a great deal of awareness about the conflict between the desires of industry (more, faster, always) and the needs of those working in it.
The Company in Conrad's Heart of Darkness is attempting to thread the needle of maximizing their profits while appearing to care for their employees. They do not want to be legislated out of existence, so they pretend to their stakeholders that the colonizers treat the native Congolese fairly and work with groups such as the International Society for the Suppression of Savage Customs to "civilize" the territory. In truth, they brutalize the natives and work them to death in the service of making money. The pretense the Company keeps up in Europe is abandoned on the Congo's banks.
The economic force of the Company is such within its home country that nobody cares to question how it manages to extract such massive profits from the Congo while also treating its workers fairly. The Company's public relations officers are careful to maintain a facade of enlightened imperialism to keep the social welfare campaigners off their backs. What Marlow sees on his journey upriver belies what he was told before he left Europe: the abuses are appalling, and the workforce are literally enslaved. The Company's star agent, Mr. Kurtz, is a monstrous sadist who has lost both his inhibitions and his mind while working for the Company, corrupted by the destabilizing influence of being in such a foreign place, with no other goal to cling to but "profit."
When Marlow returns to Europe, the ugliness he saw in the Congo has no place in the public view of the Company or its mission. The Company in this way is a bit like a "sausage factory," and the public do not wish to know how their "sausage" is made. This is the true face of industrialism, its purest aspect, untrammelled by laws. A society that is built on industry runs on the profits from that industry and, ultimately, may not care how those profits are obtained. If the industry is sufficiently far away, there is no way to regulate it; one cannot see its "inputs" in terms of labor, only its "outputs" in terms of money. The cost is enormous—human lives are being fed into this industry—but the outputs are the same. Conrad is not advocating for a return to a pre-industrial way of life, but he is exposing the hidden ugliness, the heart of darkness, at the core of the industrialist philosophy.
https://dictionary.cambridge.org/dictionary/english/industrialism