"coltan for smartphones" is a distraction.

It is coltan and moreso cobalt that is used in the manufacturing of lithium Ion batteries for electric vehicles, of which China is the world's number one producer. Incidentally, China is also the number one recipient of Congolese cobalt, exercising a monopoly over 95.9% of Congolese cobalt exports. In other words, it is Chinese social-imperialism that is the principal oppressor of the Congo.