Studies have found that caring seems to start at about a GDP per capita of $10K or so.
The depends on the size of the coalition that the government's power depends on. If the government needs the support 25% of voting citizens (a majority of legislators, each elected by a majority of constituents), then the citizens can likely pruessure their government to do something.
If the government's power depends on 300 high-ranking administrators and military officers, then it would be stupid of a ruler to enact such legislation. Doing so would reduce the amount of money flowing into government coffers and would threaten their ability to lavishly reward the generals. That could lead to a coup and to the death of the ruler.
Seems intuitive that there is a minimum threshold of confort for political participation
I just don’t agree with that. There are many ways to improve this situation. Apple has done a lot to improve their supply chains and the conditions workers work there. As far as I know, Apple has gotten completely rid of child labor for their products because of its high standards. If more companies would take that stance, there would a lot less child labor in total. Although I believe Apple made a pretty big difference because of its size.
Furthermore, the government should regulat how imported goods and raw materials should be mined. They should have clear guidelines what is allowed and what is not for raw materials. There should not be a loophole for the supply chain. Every company chooses their supply chain and is thus responsible. If every company suddenly demands that their supply chain will not employ children and use safer techniques in their mines, the supply chain will make sure demands are met.
Employing such regulations is not unheard of either. The US government already is pretty strict about bribery in foreign countries, so they should be able to place similar regulations. Enforcing such a regulation can be hard but it is possible. If companies cheat, they will get chaught eventuall and if they are fined appropriately, it should not be worth the risk.
Even getting right and left wing people to vote for that should be easy. The right wing can use that regulation to keep the mines in the country and protect jobs, and the left wing can say it is better for the environment and humanity this way. The real problem are lobbies, though. There are a lot of companies which would suffer from that a lot and they are willing to spend a lot of money on lobbing. Maybe Apple, combined with Tesla and other environmental responsible companies can make a difference.
Just hoping that the standard in another countries suddenly improves a lot is not enough. We have no control over that country and many thing can prevent that. Furthermore, this just shifts the mining to another country and it will continue there. By applying regulations which set standards how materials can be mined, including requiring a living wage for that country, Afria has a good way to raise their overall standard.