But beyond that, I think the Opiod and Fentanyl crises (or crisis, depending on how you see it) has really discredited the libertarian-leaning argument of simply decriminalizing everything, hoping that people don't fuck up their own lives

That's not the case. Fentanyl only exists in huge quantities in the illegal drug supply because of prohibition making lesser opioids less profitable to sell and smuggle. The drugs can't be regulated if they are illegal. What we have now with the drug black market is essentially a libertarian's totally unregulated dream market. It shouldn't be left up to a market at all, ideally we would see government programs supplying people with a history of addiction their drug of choice so they don't turn to using dangerous, stepped on shit they bought off the street.

Other than that, decriminalizing everything is absolutely necessary. We can't be putting people in prison for being addicted to drugs.