In a sufficiently wealthy society we would never kill anyone for their crimes.
In a sufficiently wealthy society, there’re far fewer forgivable/tolerable crimes. I’m opposed to the death penalty in current US situation, mostly for knowledge and incentive reasons (too easy to abuse, too hard to be sure). All of the arguments shift in weight by a lot if the situation changes. If the equilibrium shifts significantly so that there are fewer economic reasons for crimes, and fewer economic reasons not to investigate very deeply, and fewer economic reasons not to have good advice and oversight, there may well be a place for it.
In a sufficiently wealthy society, there’re far fewer forgivable/tolerable crimes. I’m opposed to the death penalty in current US situation, mostly for knowledge and incentive reasons (too easy to abuse, too hard to be sure). All of the arguments shift in weight by a lot if the situation changes. If the equilibrium shifts significantly so that there are fewer economic reasons for crimes, and fewer economic reasons not to investigate very deeply, and fewer economic reasons not to have good advice and oversight, there may well be a place for it.