If you're making the case that drug cartels are repulsive, you'll not get an argument here or, I hope, anywhere.
Prohibition of alcohol in the USA fuelled the rise of bootleggers and organized crime. The ending of prohibition ended that business for them. Why not do the same for drug cartels?
We can't keep drugs out of prisons. Prisons have locked doors and we know everyone going in or out. Do you really think we can stop drug trafficking in a free society? Do you think all the police forces in the world stand a chance against that level of black market profit?
You are missing or sidestepping my point: it's about the
will to beat the problem.
The makers are just one fraction of the whole: the people who run the rings, import, make stuff locally, distribute, they are the problem within the domestic part of the situation. And they are the people who can be dealt with locally. Of course drugs could be kept out of prisons: just as you can keep dangerous materials off aircraft you can prevent them getting into jails. The missing link is the will to do it. That, and penalties to match the consequences of the crimes. Less attention to the "rights" of inmates and a concentration on keeping drugs out of reach would be a start.
The huge profits are only there because the risks are worth taking because the chances of the capos being nabbed are very low. Why? I doubt it's because the police don't have the technology or resources to find them; I think it is because they are kept immune from authority. And where you have a society of dimwits ready and willing to abuse themselves with substances that will probably ruin their lives, it is pointless depending on them to provide solutions. The best you can do is catch them early: toss them out of school or university if that's where they do their thing; let their friends realise it is not fun and games, that it all comes at life-changing price. Set example of consequence.
As for the bootleggers: they hardly kept low profiles. They were popular characters, criminal stars, even. Their immunity was even more obvious than that of today's lot.
A start could be made by investigating the funding of some of those wonderful palaces that grace the Intracoastal Waterway; the funding of some of the larger yachts all over the Mediterranean; yacht clubs have waiting lists, and the last time I heard, the local one wants about €23,000 to join and you still won't get a berth to buy. Wonder about those folks who can buy multi-million pound apartments in Monaco and London, and on and on. By no means do I suggest they are all crooks, but you would be very unlucky not to unearth one if you looked in the right place. As I say, it's a matter of will.