If you buy $unbranded thing you have absolutely no idea what went into it.
If you buy from $huge_brand, their supply chains are closely scrutinised by rights groups.
They put out reports, activist investors pressure the company, internal esg & pr teams get antsy and put pressure on the suppliers or drop them.
I kinda hate the future, but basically only huge brands can be held accountable and contribute to ending these labour practices (without regime or legal changes in the source countries, that is).
So uh, support global mega corporations I guess? (and be sure to switch your 401k to an ESG fund) :/