https://www.afr.com/world/asia/singapore-executions-touch-22...
This article cites Singapore saying the existing laws mostly get low-level users and not kingpins because kingpins operate outside of the country.
https://www.vice.com/en/article/singapore-drug-executions/
Decriminalization of drug use doesn't have to mean decriminalization of anything else. Thieves and murderers should be prosecuted regardless of any state induced by the voluntary ingestion chemicals.
Ideally we would pick one or the other on a drug by drug basis. Executing people for selling weed isn't something I actually want, but neither do I want them simply imprisoned or fined either. But with shit like fent? Trying to find a single policy to fit both drugs is inane.
Anyway: Capital punishment is an elegant solution.
Might as well talk about drug policy in South Sudan to be honest.
Edit: I will say I do have one Singaporean expat friend who finds capital punishment for drug possession vile, and cites it as one of the reasons she no longer lives there. Along with the crushing wealth disparity between the servant class and the working class. Not that it adds much to the conversation except personal flavor.