If blue collar worker single parents manage to somehow make things work, it's not unreasonable to expect the same from white collar people with much less demanding and strict jobs time wise
I don’t think we should look to the worst examples of labor standards to decide what is fair. People with healthcare can “make it work” without healthcare. People who don’t have to work 996 could “make it work” if they had to work Saturdays. Even before OSHA, most factory workers weren’t losing their fingers in meat grinders.
It is very likely that blue collar hiring, firing, promotion, flexibility dynamics are entirely different to tech.
Tech competition might be much stronger compared to whatever competition exists in a very local workshop.
WFH benefits are apparent on their own for a individual. How WFH affects diversity in a specific company maybe a useful exercise , it doesn't change the benefits much.