Given that Western over-consumption is the root cause of many of the ills you sketch (child labor, long working hours, low pay, etc.) it seems odd to focus on Amazon and expect transparency to rectify many of these ills. There’s a striking resemblance to US attitudes to illegal narcotics: blame the suppliers, rather than admitting the US’ enormous and insatiable appetite for narcotics is in fact the motive force for the existence of the supply chain in the first place.
Perhaps if US consumers bought only what they need rather than indulging in “retail therapy” every time they felt in need of transient attention and a quick dopamine hit, clothing and other items could be produced more ethically (and therefore be far more expensive on a per-item basis). As it is, the US desire for lots and lots of things at the lowest possible prices creates the very conditions you decry in the article and assume Amazon should solve on behalf of US consumers themselves.