I'm on one of the buprenorphine variants (butec at the moment, was butrans until this year, via weekly patches). I strongly suspect there's cost pressure not to prescribe it to patients.

When I re-did my pain management course in 2015, having previously done it about 2002, they'd changed their line on opioids from "people with chronic pain don't get addicted" to "if you have chronic pain there's only a small risk of addiction", which was obviously changed because of US research, but completely non-hysterical.