Fentanyl is not a poison. It is a powerful pain killer with legitimate medical uses. I was given fentanyl during knee replacement surgery several years ago.
It’s not the substance, it’s the user. We ought not to waste $$billions$$ reviving overdosed druggies. Drugs in those quantities are a suicidal impulse. Kinder to let them go.
As with many useful chemicals and drugs, “The Dose Makes the Poison”. The problem with Fentanyl is the incredibly small dose that can kill you.