If employees are treated so poorly they would leave, it's not like we force people to keep their job. If you prefer to pay more, it's your choice to buy from smaller companies.
Everybody is free to leave and free to find new jobs, im not sure where you get the idea that isn't the case.
Also how is it stealing value to pay less than the profits made? You realize a company has to make profits to survive, right?
How is the US arguably the most successful country on the planet if stuff is really as bad as you say it is? The US is far from perfect, but it's impossible to deny it's one of the best places to be and people risk everything trying to get in wanting a better life.
Unless that's part of the agreement (pretty sure it isn't) then they are free to do what they want, especially if the government becomes hostile to them.
You are living in fairy land and way outside the realm of reality. What you want isn't realistic, and it doesn't matter how badly you or everyone else wants it. I'm being realistic here, not falling deep into fantasy land.