It’s strange to present them as some sort of solution in this case, where there was widespread engineering and management cultural issues, and would therefore somehow have prevented major air disasters.
Workers rights and forcing higher wages might be great for the working poor and it might actually make economic sense in certain niche industries where protectionism can prevent the companies entire business being eaten by Chinese/global ones without the myriad of rules and restrictions that unions being - rules that go well, well beyond wages. But it is not some grand solution to high level engineering problems caused by stupid cost saving priorities made by C-class executives and other weakness in quality down the line.
Further, non-union companies are more often the default these days, and tons of these companies are producing high quality American engineering and manufacturing products.
Even in the romanticized history of US labor only a minority of working Americans were ever in unions even during the hayday when it actually made sense to have unions (when America had tons of factories and manufacturing but little global competition and plenty of protectionism to artificially keep them alive).