The sad thing is that speed in apprehension and prosecution has been shown to be the most important element by far for deterrence. Marginal deterrence effects of harsher sentencing for most crimes is basically nil at this point. The complexity of plea deals and the incentive they create for defense attorneys to drag things out breaks the perceived cause+effect dynamic, at least for typical criminals. The system just becomes this juggernaut where both guilty and innocent people alike feel it's utterly capricious.

At least until the recent tough-on-crime regression almost everybody agreed the system is too harsh. Even conservatives were on board with lighter sentencing. But unsurprisingly that broad public support didn't persist for long because the structural incentives of the system push it toward greater dysfunction. Without structural changes lighter sentencing alone just makes it more profitable for criminals to roll the dice. The complexity of the system evolved with the harsher sentencing, but can't change back as easily as sentencing policies, so we fall back to the old equilibrium that slowly gets worse along every dimension--fairness, cost, deterrence, etc.