To clarify just a bit, the drug using/OTD kid has some free will. However, he has the responsibility of having forfeited much of it by assuming an addiction. The others in the environment that affect the situation have presumably not lost any of their own bechirah.
While I am not advocating absolving a drug user of his responsibility, I will also look to the broader picture for the other contributing factors.
Meanwhile, the kid often gets into treatment, rehab, therapy, etc. The parents often participate in treatment and therapy. Yeshivos have hardly changed or been willing to look at themselves and their systems to make needed changes. That’s the ire of so many commenters.