> Keep in mind that the world operated on subsistence farming before 1800
Yep. But I think a big difference here is between subsistence farming and serfdom on the farm you lived in vs sending kids into the wool factories with unbreathable air. The testimonies from factory inspectors is mind blowing.
> What eventually saved children from this was the rising productivity that came from industrialization.
Eventually, thankfully yes. But the Factory Act also mandated maximum hours children could work per day, making employing children expensive as they needed double the number of children to work in shifts, which eventuated to banning shift work for children altogether (because they weren't allowed to work past certain hours making shift teams useless).