I'm a prison nurse and can assure you it is no holiday camp
Yes you will always see them having 3 meals a day , roof over their head and access to healthcare etc , some have access to education and the gym - that's 40 minute of an otherwise locked up 23 hr day
What you don't see much of is the low quality food , the cell conditions , the regime , the bullying , harassment , assaults , regular deliberate self harm , mental health deterioration
I am in favour of the death penalty for certain crimes but the process would be impossible to manage so will never happen