the video is all about the subcontractors, so i guess they are the ones being hurt.

i suspect the problems are:

subcontractors are small businesses that don't have the resources to cover those liabilities or fight lawsuits from customers, nor do they have the resources to fight amazon to make it pay their share.

maybe getting insurance is not enforced, so those who don't pay for insurance are cheaper.

amazon uses their negotiation power to demand favorable conditions for themselves from subcontractors.