I do feel like a disconnect in the "were Jason's methods effective" argument is that many people don't know how addiction actually works! They don't know that quitting cold turkey can kill you! They don't know that organized crimes default business model is selling and recruiting to young people so they'll have repeat customers for life! And, importantly. This one is really important. I need everyone to listen to this above all else. People have the right to do drugs. Adults with their own income can choose what they do with their body, even if it is bad for them. It's their choice. Taking the choice away from them is 1. Not possible (Think of Prohibition, when people turned to shadier means of getting alcohol when it was legally banned) and 2. Will inevitably lead into taking other choices away from them (who gets to decide what's bad for your body? If you give that power to the law, they WILL abuse it. Every time).
Which brings us back to Jason's set up! In Lost Days he kills a dealer, not for dealing drugs, but because those drugs are laced. If people have the right to choose to take drugs, then they also deserve clean drugs, clean needles, easily accessed narcan, medical attention that doesn't lead to punishment by law enforcement. In UTH, obviously he has his no selling to kids rule, but he's also still enforcing clean drugs, which is better for existing addicts than simply killing all the drug dealers in Gotham and taking away access to the drugs. People will still find a way to get drugs. Criminalizing something has never stopped it from happening. If Jason did, somehow, shut down the drug trade completely it would just lead to more desperate, dying, people and where there are desperate people, there are the groups and policies that take advantage of them - especially in a place like Gotham. Jason is REGULATING the industry, instead of punishing its existence, like say, the prison industrial system would.
I also HATE when people bring up the Catherine of it all because it's always the most ignorant, uneducated, unresearched take I've ever seen. "Jason sells drugs!! Like the thing that KILLED his MOM and Jason HATES addicts!! LIKE HIS MOM!!" What are you talking about. In his original Robin run Cathy was self medicating a terminal illness. She was dying anyway. Her addiction wasn't a moral failure because there is no morality to addiction. It's another form of mental illness. It literally reconfigures your brain. The only failure that led to her addiction is the failure of the medical system.
And this is a reality for many addicts! When mental Healthcare isn't readily available/being too honest leads to police intervention or forced hospitalization, when Healthcare is too expensive for most people to be able to pay for out of pocket and insurance companies put you through 80 hoops and deliberately prey on the less educated and informed, people are going to turn to self-medicating. In Catherine's case, her addiction was a form of assisted suicide kind of. Taking away access to drugs wouldn't have saved her! She just would have died slower and in more pain! Why would Jason want that for her? He loves his mother he's never resented or blamed any of them!! Even in the fuckin N52 she is shown to be deliberately preyed upon by men that know she's vulnerable and not in a position to, say, vet where they're getting their stuff from or the quality of it! And in Rebirth, Willis tells us when he met her as a teenager, she was already a user! Jason's policies WOULD have helped her!!
And of course when we're talking about harm reduction we have to talk about rehabilitation. People deserve, and need, access to things like homeless shelters that don't call the cops or kick you out for being high, rehabs with the resources and manpower to actually make a difference, ect. Ect. And it would be ideal if Jason had been working on that too WHILE regulating the drug industry.
But 1. The comic is not from Jason's perspective, and it doesn't focus on everything he does. We are for the most part limited by what Bruce knows, and what Bruce knows is, by his own admission, not a whole lot. Not enough. Even when people do point out to him that Jason's methods are working, Bruce gets pissy and locks in on all the bad. So it's entirely likely that if Jason was funding those things, Bruce wouldn't even be looking for it, if he could trace them back to Jason's operation at all.
2. Jason was not operating very long!! He was only a crime lord for a few months, maybe, before the confrontation with Bruce!! He had the takeover planned, clearly, and he executed it quickly, but harm reduction facilities like that take time if you want them to be legit and they require people's trust. And in Jasons case it would be very important for him to make them unable to be traced back to him (by Batman or rivals) which would take even more time. And also Jason really wanted to kill himself which really put him on a time crunch.