I have seen one company where they had outsourced the process of becoming a supplier for that company to a compliance agency, because the paperwork was getting too much for the company itself. You had to provide certificates of no child labor, confirmation that you permit union activities, a detailed list of workplace incidents, detailed list of harassment complaints in the last ten years, safety material handling, description of your rat-out-a-colleague (whistleblower) system, etc.
The flip side of this is of course that companies use a mutli-level supply chain precisely to avoid responsibility for child labor, slavery, unsafe working conditions, illegal environmental practices, product safety, and so forth. Outsourcing isn't just about saving money, it is also a way to take a bunch of problems you don't want to worry about and handing it over to someone who won't worry about them for you.
It would be nice if some of these things were solving actual problems, rather than just creating more paperwork, but sadly that does not appear to genuinely be the case. A few companies may be trying to actually clean up problems in their supply chain, but it is trendy, and it is much easier to copy someone's paperwork than their actual work.