"it happens in China and we still buy the products."
Yes, it does, and of course we do.
We fuel the child labour problem because we constantly search for the cheapest deal whenever we buy something. We want the technology, or the trainers, or the power tools at the lowest price we can find, and we spend a lot of time researching. It forces manufacturers to try to find ways of driving production costs lower and lower, and many Western technology companies outsource supply to South East Asia. There the temptation to employ very young workers is huge - families need every bit of income they can find, and they happily see their children going off to assemble electronic components, or shoes, or whatever is being made for (mainly) foreign companies.
We're the culprits, but I don't see many threads in our forums asking 'where can I get a laptop that has been made without exploiting young workers?' Usually it's 'what's the best value for money laptop deal?'