There's modern day slavery in the world. Today. Even in the US we have compelled labor - it's a whole thing in the Georgia prison system. Those McDonald's burger flippers are essentially slaves, and I bet you didn't know that.
But if we subscribe to the ideology of "X has it worse" nothing would get done, ever.
The reality is even in seemingly prosperous industries workers, laborers, DO NOT have equal leverage in negotiations. Not even close. What you're describing is relying on the generosity of the corporations who employ them. A fine strategy, but hardly sustainable. They, too, can look to improve their situation.