The Unions is often all there is to protect the work force who were abused for years and years before they organized to improve working conditions and get a better wage. The Wealthy owners no longer could squeeze all the profits they could out them even cause deaths to come by in their thirst for ever more profits.
Unfortunately, once the Unions gets well established and did the initial improvement on workers' health and wage situation corruption sets in and criminals begin to use the Union funds for their own purpose and get into partisan politics that reduces their drive to maintain support for the Union work force.
It was the nefarious excesses of Jack Ass Morgan, Carnegie, Rockefeller, Ford and other over wealthy jerks of a Century ago who squeezed their work force dry to pad their bottom line finally caused the workers to start Unions as a means to demand safer work conditions, eliminate child labor, institute an 8-hour workday and better wages.
Unions exist today because most workers learned NOT to trust the Wealthy owners who has a long poor record of treating their work forces fairly and decently.