The workers are hardly benefited when they die, Being killed is not beneficial to anyone.
The workers weigh this in the terms they are working under, they choose to work in bad conditions because the alternative is unemployment , which is hunger in some parts of the world .
Conducting business and distributing pay the workers often spend well and send their children to school , with a lunch.
When fed children grow up knowing how to read , the population grows a lot more engineers and doctors than when unfed children grow up unschooled.
So even the most modest pay for the most dirty and dangerous work is better than no work, an improving economy increases the demand for safety along with the demand for honest regulation of industry.
Then when there are alternative jobs to be had , these racing to the bottom jobs run somewhere else, somewhere that these very modest jobs are the best to be had.