Yes, what you describe is difficult. For us in the West it is not always easy to know the right approach when dealing with developing countries with issues such as child labour.
We could boycott or stop buying the products they make with child labour and make them ourselves. Yet, that doesn't necessarily solve the underlying issue. Suddenly the child and her family are starving because nobody are buying the things they make.
Another example is when we send in food aid to African countries struck by famine. The famine has pushed up food prices. People struggle to get food, but farmers are making more money and using that money to expand food production.
Then in we sweep with massive drops of free food. And with a stroke nobody is buying food from local producers anymore. Why buy overpriced food when UN distributed food from the West comes free? The result is economic collapse from farmers. They have to scale back food production and now the country may end up less self sufficient in food.
My point is that many good intentions can have unintended bad consequences. Many good intentions don't work at all. In Norway in the 1970s we tried to improve the income of fishermen in Bangladesh by sending them modern Norwegian fishing vessels. A year later they were broken. Why? Bangladesh entirely lacked the infrastructure to serve a modern fishing fleet. They did not have repair shops with the skills and part to service modern boats.
It shows how everything is tied in together in a complex web.
What you describe about people who do things under harsh conditions which ultimately we benefit from has parallels with environmental policy. You may want to do the right thing and not use fossil fuels but you cannot control what fuel was used to transport goods to your local super market or the fossil fuel used to harvest the grain. I might want to fly an airplane running on biofuel but as a single passenger that is not my choice. Nor can I decide the fuel on the bus I ride.
Ultimately we must accept that each one of us do these carbon foot prints we may object to. As individuals we cannot change it alone. However, we can bond together through collective political action and activism to facilitate change. I try to vote on green parties and promote them as best as I can.
I am not sure what the right choices in trade are. Should we not use cobalt from the Congo because it is mined under bad conditions, where people are exploited. For many this choice is simple. I am not so sure. I don't see how Congo is better of by us not trading with them. Even cobalt extraction happens under bad conditions it brings the country money.
We could probably produce Cobalt in my native Norway, but then who profits? That will only be Norwegians. Congo citizens will not see any of that profit.
That is a challenge facing many poor countries. If they operated mines and factories by the same high standards and pay as in the West the would not be able to compete at all. A Cobalt mine in Congo trying to extract Cobalt using Norwegian standards would easily get outcompeted by a Norwegian mine?
Why? Because rich countries like Norway has far more political stability, better educated population and better infrastructure, stronger protection of investments, which gives a massive advantage. Less developed usually only manage to compete by lowering standards and salaries.
That may seem like a bleak perspective, but I do think every country can pass legislation and effect practices which improves working conditions to a minimal acceptable level even if they cannot reach the standards of the developed world.
I see the same in my industry. There is no way a Norwegian company would outsource work to an Indian company if they paid the same salaries as in Norway. Dealing with different time zones, cultural barriers etc means there is an extra cost of doing software development in India. That disadvantage can only be offset by significant cost reduction.
Personally I am skeptical of too much free trade and large multi-national companies. These companies have market power to squeeze and exploit local producers. OTOH some large companies raise standard. E.g. as far as I know Apple factories in China have much higher labour standards than what is common in the rest of the country.
It isn't easy, but I am a social democrat in large part because I believe in government. I believe governments can create regulations and pass laws which can help offset many of the injustices suffered in poorly regulated markets.
