I do not think punishment is a good deterrent, no; I think the data more or less says that as well. If you look at Scandinavia, where they generally have a much higher emphasis on reform instead of "punishment for punishment's sake", and they also have a substantially lower recidivism rate compared to the US.

Now obviously, I'll fully acknowledge that it's not completely apples to apples; there almost certainly a million differences between the US and Scandinavia that contribute to differences in crime statistics, but I think it does demonstrate that reducing emphasis on punishment doesn't turn the world into this post apocalyptic dystopia.