What is the main idea of the chimney sweeper by william blake?

The poem "The Chimney Sweeper" by William Blake is part of his collection Songs of Innocence. The poem is about how these children are devoid of their childhood and innocence, and are forced to work in really harsh conditions sweeping chimneys in all kinds of weather, until they get sick or die. Even if they do get sick, nobody is going to help them, so they will ultimately suffer until they pass away. It is a poem about the horrors of orphaned children who have no one to take care of them, so they have to survive any way they can and hope for a better tomorrow.