see, i'm pretty soft on crime in general, but when i say i don't believe in punishment, and that incarceration should be a mental health concern, you have to realize this comes with a wholesale discarding of much of the existing legal precedents.
iirc, the literature suggests four valid reasons to incarcerate somebody, but i can only really accept one of them, and that is to protect the safety of the community. yet, in doing so, i take that single reason extremely seriously.
while i understand that the existing precedent suggests that punishment for multiple crimes should not be excessive, if we flip the issue over and look at it from a community safety perspective, multiple crimes of the same sort over a period of time becomes an issue of grave concern. this person does not appear to have made a mistake, but rather repeatedly carried out the same behaviour. that suggests some habituation to it, and the need for exceedingly strong intervention to correct it.
permanent incarceration via locking somebody in a cage is not a particularly good way to correct for behaviour, granted. but, in situations where it is decided that intervention is unlikely to be successful, it becomes necessary to protect the community.
that said, i would envision the prisons of the future to look more like enclosed communities than torture chambers. if we decide that people need to be removed from society to prevent them from harming others, that should not prevent them from being able to exist in some kind of relative comfort.
https://www.theglobeandmail.com/canada/article-reduced-sentence-for-serial-sex-offender-matthew-mcknight-spurs-uproar/