I used the think the death penalty had lost its deterent when it was with lethal injection after 15-20 years of appeals . I thought it should be televised and at half time of big sporting events. And the method should be swift and visually shocking and confirmable. So guillotine with a white cloth running down to a basket. Instant replays on the roboteon was in my mind.
But there are bad cops and prosecutors who have wrongly put people in jail and luckily they weren't killed swiftly and found innocent and released after sometimes decades.
Selling drugs isn't a victimless crime.
Also there are differences in punishment. Look at the Sackler family . https://en.wikipedia.org/wiki/Sackler_family#:~:text=The Sackler family is an,2023 Netflix mini-series Painkiller.
To fix the root cause you would need to stop abusive parents, hunger, provide access to medical care, good education. Plus I'm sure the list goes on and on and may include DNA selection.