Imagine another scenario. You are my neighbour. I spill some poison on the ground. Your child gets ill. Am I at fault?
If it is a feature the customers care about they will market it. But frankly customers just want a better price today.
A number of markets have few competitors which means it's beyond easy for all the companies to externalize everything.
Further, some products have deep supply chains that are easy to mix. Consider copper as an example. A responsible company will want to use recycled copper as much as possible because it's cheaper. However, can anyone realistically validate that none of that copper came from stolen cables or bad mining practices?