You seem to be convinced that there’s some magically bad crime that would make me turn on a dime and say, “oh, of course, those people should be tortured forever.”
one thing I am convinced of is that we can invent a non-torturous way of removing someone from society to protect people from them. The fact that a serial killer's rights are restricted and they're not allowed to leave a building doesn't mean our post-abolition institution includes all the other things that are wrong with modern prisons.