The modern liberal state tends to reject the idea of criminal justice as revenge-driven as opposed to being reform-driven, therefore execution is treated as a solemn realisation of the idea that the criminal is unreformable and will only be redeemed through death as opposed to a vengeful process of making one feel something equivalent to what the criminal made their victim feel. To an extent, I disagree with this, I'm of the opinion that in the case of certain crimes, the perpetrator has become unworthy of the effort and care involved with attempting to reform someone, and in those cases the proper punishment is a performance of ritualistic retribution for the sake of the victims.