This seems like a powerful concern in theory but the facts make me more optimistic. I haven't found, say, OSHA to be toothless in practice, the DOL routinely brings aggressive overtime violations cases, and enforcement of the civil rights act against particularly southern hotels and gas stations by federal courts are all powerful counterexamples.
They are not comprehensively solved problems, but clearly demonstrate that organs of state power can and have been used in defense of marginalized groups. I'd say especially Federal courts, but several agencies have done impressive work too.
OSHA is toothless in practice. For large companies the fines are negligible.
https://www.ishn.com/articles/108358-osha-issues-tiny-penalt...
"OSHA has fined Tower King II Inc. $12,934 for the death of three workers who were attempting to install a new antenna on a communications tower in Miami. This is the maximum fine for one serious citation. "
"U.S. Rarely Seeks Charges For Deaths in Workplace"
https://www.nytimes.com/2003/12/22/us/us-rarely-seeks-charge...
Also, under Trump
It's not exactly like children losing arms to looms and being locked inside enflamed textile mills.
The fact there's still some work left to do doesn't imply we've made no progress.
It does show that unions haven't been able to comprehensively fix these issues either, though.
>Generally we need to move those solutions into less partial laws and courts, instead of creating another unchecked center of power over workers.
Those most in need of the labor rights and respect unions traditionally afford are often those who have almost no access to the legal system. Fundamental problems like that are very difficult to fix, so in the meantime unions are the best way to accomplish that goal.