Highly addictive drugs aren't a thing you just start and stop taking... Opioids are intensely addictive and Purdue repeatedly marketed Oxycotin as a non-addictive Opioid, there is even video of a Sackler talking about how much the sales team should be pushing the non-addictive qualities[1] as a benefit when dealing with Doctors. They also used the ye olde drug rep hard sell sales tactics to push it on Doctors in exchange for monetary compensation and in kind compensation when the US made direct monetary compensation illegal.
Purdue is a huge part of this crisis, but they shouldn't be singled out - the marketing that pharma companies engage is constantly contributing to the ill health of Americans through toxicity, unnecessary side effects, stress from financial pressures and, sometimes, direct poisoning.
Please do a bit more research into this crisis and it's causes.
1. Specifically, false qualities that Purdue actively hide evidence of.