[citation needed]
With all due respect, I think this statement is false.
If you live in a society that can, thanks to advanced technology, provide for the material needs of all, which, if you live in a rich Western country, is basically already the case (remember the last time you had to actually grow your own food? Probably several generations ago), you don't need to execute anyone.
Indeed, given that in such a society, where there are no shortages of food leading to "only one of us can eat" type scenarios, I'd argue that hurting individuals would lower aggregate wellbeing, because you're hurting people beloved by other people (the elderly? Turns out their grandchildren really like them and get upset if they die? fat people? Turns out their friends really like them and get upset if they die. the disabled? Turns out their family really like them and get upset if they die).