The problem, as the poster above you noted, is defendants having access to public defenders, which are underfunded by the state, despite being central to our judicial system’s smooth functioning. People can contest, but if they don’t have a lawyer to help them make arguments or to even know what their rights are under the law, then contesting anything is going to be tough for them, especially when they are going up against well paid and funded prosecutors.
The system is stacked against people without means, essentially.