I was thinking a Dickens -era specialist would stop by, here, and you might consider posting again for a longer answer. But I think it's safe to say that Dickens was not leading the charge against some of the social ills he portrayed in Oliver Twist or his other novels: he was mostly catching a spirit of the times and giving it voice. By the time Oliver Twist appeared, the Chartists were asking for more democratic government, the Anti-Corn Law League was asking to repeal the Corn Laws that essentially subsidized wealthy landowners and kept food expensive, and ( perhaps specifically for Oliver Twist) the 1834 Workhouse Poor Law was also being opposed. That had recently replaced the old institution of the Poor House with a more punitive institution of the Workhouse which was designed, in a Benthamite spirit, to be an unpleasant place in order to discourage people from taking advantage, force them into regular work if they could do it. Long-standing traditions of public doles of food ( some dating back hundreds of years) were also to be discouraged because they did not have some sort of requirement for work. That Benthamite nightmare was the one Dickens portrayed in Oliver's orphanage. The cold-blooded economic calculation of Bentham and Malthus also fill out the characters of other villains in his books, like Ebenezer Scrooge, whose "decrease the surplus population" remark is very Malthusian. But Dickens was not alone in noticing that the new Victorian industrial economy was corrosive to families, and writing about it. Henry Mayhew began his important series of documentary articles on the London poor in the 1840's, trying to raise awareness that the booming economy was not enriching the people at the bottom of it.

Dickens would also jump into other movements: the fossilized Chancery Court that decided nothing, when he wrote of it in Bleak House, was in the process of being reformed. He was perhaps a little ahead of his time in his treatment of debtor's prisons, perhaps because his father had been put into one. His Pickwick Papers and Nicholas Nickleby would precede the destruction of the Marshalsea in 1842, though Little Dorritt would come afterwards. Certainly those novels publicized the idiocy of that institution better than anyone else had ever done before.

Henry Mayhew: London Labor and the London Poor