Child labor is a complex issue, in the mining sector in developing countries with a poor or non-existent social safety net we sadly see children working in the informal sector / illegal and artisanal mining.
Its unlikely that any child given the choice would rather toil in the dirt than attend a school and learn to read or enjoy leisure time with their friends and families however it may also be that the economic situation for them and their families means that working is better than the alternative.
Poor families whose income is around the subsistence level often have little choice and there can be unintended consequences.
Yes lets address modern slavery and child exploitation in particular, that means also addressing the economic drivers.
On untended consequences a further reading suggestion is "A Dark Side of Institutional Entrepreneurship: Soccer Balls, Child Labour and Postcolonial Impoverishment - Farzad R. Khan, Kamal A. Munir and Hugh Willmott"