A group of people have been living off the land for centuries. At some point a government comes in and takes the land from them to sell to a factory owner so the government can profit. With no land to farm, working at that factory becomes their best option. But the workers get abused. Women get raped. Their pay is stolen. Still they don’t have a better option. They try to unionize. The government police come in and kill the union leaders. The people keep working there because they have no better option. That does not mean the situation isn’t horrible.
It’s not enough to say they chose this job freely. A lot of coercion goes on. How prevalent is this stuff? I’m not sure. But don’t assume most sweatshop workers just decided this was best with no coercion. People like you and me aren’t paying much attention and a lot of bad stuff happens when we’re not looking. It doesn’t help that corporations benefit greatly from reduced labor prices and so the media and advertisers don’t want to talk about these issues.
Here’s a great documentary on some of these issues:
Rural life is dull, you have a limited social circle and limited access to culture. And you have few opportunities. People today still crowd into overpriced cities with poor living conditions, because they dream of 'making it', and they can't bear the thought of toiling away at agriculture (or at a lesser job).
In China, an entire generation has been uplifted out of poverty by voluntarily relocating off of farms and into manufacturing jobs, and it's been so successful that it's cited as a reason for the popularity of current authoritarian leadership.
We're not talking about subsistence farming vs driving for Uber here.