At an even more meta level, whether interests are even competing is itself something subject to differing definitions.
Take the word “regulation”. According to wiktionary, it comes from “regō”, which means “to keep straight, direct, govern, rule”.
Direction requires a desired destination. We would like to steer the environment away from highly adulterated/dangerous drugs, away from harmful drug use generally, away from territorial violence, and away from drugs being sold to children.
Those that advocate for “deregulation” as well as decriminalization are really advocating for emergent peer to peer regulation instead of regulation by fiat. They generally think the best way to keep systems accountable and moving in the desired societal direction is for individuals to have as much freedom and direct feedback as possible about the consequences of their actions, which they argue leads to better individual decision making due to that better feedback.
Those that advocate for government regulation generally think it’s easier to keep systems accountable if you concentrate the most competent and responsible people into an explicit, transparent enforcement organization, which they argue leads to better decision making due to that better guidance and enforcement.
The former worry most about ineffective or bad actors in government enforcement systems distant from feedback/information. The latter worry most about ineffective or bad actors in the populace that are allowed to grow without coordinated enforcement/ability to organize.
I don’t think a lot of the arguing over different solutions to drug problems are really arguing about incompatible approaches, they’re just focused on different parts of the problem.
In my personal view, I think the BIGGEST problem from all camps is a lack of desire to really confront the core issues/invest the time and effort needed to actually solve these problems, which is a lot more about sitting down with people in very unpleasant situations/doing a lot of very difficult therapeutic communication, dealing with personal anger at irresponsible people, dealing with our disgust, not liking what we see reflected about ourselves, not liking to admit how much we actually DON’T control, not liking to acknowledge our own hypocrisies/how we contribute to the problem, not liking to acknowledge vast experiential differences and how important close connections are, not liking to admit how many people don’t prioritize themselves or others and are ungrateful/resentful, etc. We’d like to simply “get someone else to deal with it”, whether that be the government, the immediate family/individuals themselves, an app, a magic pill, some kind of secret drug problem destroying machine, etc.