"And we spend tons of money before executing anyone... years and years often in prison, decades even. It's not money saving at all"
No 'we' don't if you're meaning uk as there is no death penalty in U.K.
Personally I am anti-death penalty, but for different reasons.
A - it's too damn good for them! Proven by the likes of Ian Brady, Fred west who didn't want to live with public knowledge of their guilt, incarcerated.
B on the VERY rare occasion of innocent people being convicted - you can't reverse a death sentence. You can't give someone years of their life back either but IF they're found innocent then they have a chance of a new life.
C societies with the death penalty tend to have more violence generally.
D it gives certain types more motive to kill victims, not less.
However, I do think sentencing is woefully lenient, that part of the reason there are periodically calls for a return to having a death sentence is because too few of the very WORST perpetrators get true life sentences - which is what was promised when the death sentence was abolished. Now you see murderers released less than 10 years after the crime! That's not right AT ALL.
I also think prisons are not as harsh as they should be. Criminals having access to material goods that decent honest hardworking people can't afford is completely out of order!
Education, physical exercise, therapy, treatment for/help with medical issues, support for learning difficulties, even treatment for addiction I understand and think is acceptable. Keep them busy with work/education etc.
Access to porn, violent computer games - absolutely not on!!
And certain crimes (murder, rape, sexual abuse/exploitation of vulnerable people) should get automatic full life sentence.