Punitive fines and fees are bad. Abuse of civil forfeiture is worse. But worse still are a minority of towns that not only are dependent on punitive fines, but that levy them in a racially biased way. See https://www.npr.org/2014/08/25/343143937/in-ferguson-court-f... for an explanation of how this helped ignite the racial tension that Ferguson had a few years ago.
> and then arresting people when they don't pay [the fine]. So what should the government do if someone doesn't pay their fine?
There's a big difference between someone not paying a fine because their flat-out broke and not paying it because "fuck the system, I'm above the law."
Zero-Tolerance and One-Size-Fits-All policies are destructively stupid and result in bad outcomes. Context matters in a system of jurisprudence, but ignoring it makes the lives of those implementing and managing them easier though, which is probably the point.