Trust me, it's not pleasant. Until some time back in India, little children were employed to roll a certain kind of beedi (cigarette like product) because their small hands made the packaging tighter, and the beedi more enjoyable to smoke. Many of these children would go on to develop skin cancer due to the exposure to tobbacco leaves. Another dangerous industry that hired children was fireworks, again for similar reasons. A place in Tamil Nadu called Shivakasi was (is) notorious for employing children to do that highly hazardous job. Most of the factories were unregistered, and therefore did not follow any safetly protocols, and every time there would be an explosion or fire, the children would die horrible deaths. That town used to produce fireworks and matchboxes used all across India and South Asia.
Another benefit of employing children is that they only need to be paid a pittance - so the employers make a lot of profit.