If I was to be convicted of crimes that could send me to prefer for decades, I’d MUCH prefer to get that sentence near the end of my life than near the middle of my life. I’m in my 40s, so if I was sentenced to 20+ years of prison now I’d miss seeing my kids grow up, miss the remaining years of a career or any chance of owning a home. If I was sentenced to 20+ years at age 70 I’d basically just miss out on my retirement and probably wouldn’t even end up living long enough to serve out the full sentence. Many people spend their final years in some kind of care facility anyway, so prison isn’t even that much of a step down.
“Dying in prison” isn’t necessarily a bad deal if it means you get to live out a full life first.