"evolution" doesn't happen this way. It happens by changing the entire paradigm. There will be a time when western civilization will be at the point where criminality of any crime will be a drop of what it is now, which is a drop of what it was over 200 years ago... but that time is not yet. But it's approaching.
But I know that the way to it is by valuing human life and the death sentence does exactly the opposite.
And ,yes, ofc, rehabilitation is key. Most of Europe's, well, civilized part of europe anyway, is focused on that.