Regardless of the method of execution, imagine knowing the exact date and time of your death and knowing nothing you could do would stop it. That is torture, plain and simple. It should be in violation of the eighth amendment.
Consider Japan, who does it differently. Death row inmates in Japan are not told their execution dates, as they had issues with people committing suicide before they could be executed. So now they only find out with just a few hours of notice when they're going to be executed. You could be sitting in your cell, ten years into your sentence, enjoying an otherwise ordinary, quiet day in prison, only to be told that it's time to die, whether you're ready for it or not, the equipment and staff are already prepared and there's no time left to argue your case.
Honestly, I don't know which one is "better". They're both cruel in their own ways.
It's been ruled that a punishment needs to be BOTH cruel AND unusual, to qualify as a violation. One or the other is fine, as long as it's not both. Scalping someone for petty theft would be okay as long as most-everyone convicted got scalped.
In this specific case, I wouldn't call it usual and it certainly is cruel.
I would also argue that, since it is not applied evenly in any way and that only a minority of people get the death penalty, even though some people who don't get it have committed worse crimes, it is always unusual. Usual is prison for some length of time, possibly life.
I would also add that SCOTUS found it both cruel and unusual at one point.
But also, apparently all of the available methods of execution barely work at all because of gross incompetence of the people who create the systems. That's the more important issue, here, imo. The state clearly isn't capable of serving a death sentence, nor do I expect they ever will be, so they shouldn't even have the right.
I'm a consequentialist with aversion to suffering, so I think there are some very rare cases where it would be warranted if reform were considered truly impossible or would cause more suffering than it is worth, such as older or insane accused with very solid evidence convictions by a jury of peers.
Hard choices exist in this world, people sometimes have to choose what they can protect.
I'm really not understanding your argument. What does this 'suffering' have to be worth? And if an elderly or mentally ill person suffers in prison, that sounds like we should make prison a less horrible place, not euthanize people we feel deserve it.
I'm operating in the very real world assumptions that the restrictions of freedom of a large class of people will never so easily be made "a less horrible place." This is far moreso true for chronic mental illness care. I don't have a plan for any of that, and it doesn't appear as though you do, either, so instead a simple solution is to only give a death sentence under very specific and hard to establish conditions agreed upon by a majority of people.
The plan is caring for mentally ill people with psychiatric supervision, possibly medication and/or therapy, something our prison system doesn't offer, not killing them. You're doing the "I shot the dog because he was untrainable and killed chickens" Kristi Noem defense, except for killing people.
Psychiatric Supervision, Medication, and Therapy don't necessarily eliminate all suffering, and certainly have no guarantee of reform or a cure. Kristi Noem had a perfectly fine young animal capable of training by qualified owners of which many were likely available in her area, she instead chose to kill her dog. This is a great example of how outcomes with excess suffering are always worse and that many people are too mentally incompetent to weigh their options. If her dog were judged by a jury, it would have been acquitted.
A judge and jury of peers adhering to very strict legal definitions and sentencing guidelines written by a democratically elected congress, because after thousands of years that's the best system we've ever developed to reduce harm and promote equality and wellbeing for the majority of people. It's not one person deciding the fate of another, it's all of us deciding the fate of individuals for the benefit of us all.
So people who have no actual expert knowledge of mental health or mental health treatment? And you want this congress to be responsible for deciding who lives and who dies?