Fuck suffering. The system should be focused first on rehabilitation and second on seperating the person from society so they can’t harm others.
The infliction of suffering does nothing to help society at all. It just creates horribly broken people in prisons and encouraging hate outside.
If someone can’t be rehabilitated I see no issue in providing a comfortable isolated environment for them. Hell, give them whatever drugs they want too, who cares, just keep them away from society.