Which doesnt work for 74% of criminals.
It does work for 26%, even despite our prisons being badly run and rehabilitation being poorly implemented.
We need to spend a great deal more money per head on prison population, because the end result would be cheaper. The prison system we have now doesn't work. For people outside of the margin of normal working society prison isn't a great deterrent and there's little or no rehabilitation, if we don't break that cycle then people will re-offend.
Because it doesn't work 74% of the time now doesn't mean that is the best we can do.