Two wrongs don’t make a right – you cannot compensate for a terrible loss by causing equal suffering to the person held responsible, even though revenge is a natural human emotion.
We don’t punish children severely when they make mistakes, even if the mistakes are terrible ( well not any more, look up the case of George Stinney ).
Now I am not saying that adults are children, they should be punished more than children for equivalent acts, plus there is a need to protect the public from offenders who may re-offend. But adults who commit crimes tend to be those who had bad childhoods, who suffer from mental illness, who have some kind of disadvantage.
A day is a long time in prison. A week is a long time. A month even longer, A year longer still. Ten years a very long time in prison. Twenty years an extraordinarily long time. These are harsh punishments, and provided authorities deem that someone has been rehabilitated, and is safe to release, this length of punishment should be enough even for the worst crimes.
This is how Norway approaches imprisonment. I would say it is humane and in the best interest of society.
It also gives some relief to the many people who are wrongly convicted. In my opinion the USA has fallen into a system of “ultimate vindictiveness” where large numbers of people are subject to unduly harsh punishments, often being sentenced to die in prison, being given no hope or reason to rehabilitate themselves. That is cruel.