Why is jail necessarily the best answer? Fines and restitution, community service, court mandated counseling, "night jail" (must report to jail after work) and

Why is jail necessarily the best answer? Fines and restitution, community service, court mandated counseling, "night jail" (must report to jail after work) and other tools would work better for preventing and correcting the harms of many (if not most?) types of nonviolent crime. Traditional jailing creates all kinds of assorted harms that actively prevent rehabilitation and which probably don't provide much deterrence. Your suggestion of reform is indeed necessary, but some of the things I suggested above would fall outside of what most people would consider "jail." We are stuck on this singular "solution", and why? It doesn't seem to be very effective.