Actually the two biggest factors for the increase in opioid prescriptions are "Pain as the 5th Vital Sign" and Press Ganey/ HCAPS

Pain as the 5th Vital Sign
https://www.medpagetoday.com/publichealthpolicy/publichealth/57336
In 2001 there was the notion that physicians were not treating pain appropriately and that we should focus more on pain. The introduced idea was treating pain as a vital sign (in addition to pulse, blood pressure, temperature, and oxygen saturation) The problem is that pain is subjective. But we were told by new standards that we should be treating the number of the pain score. This is one of the first marks and when you start seeing an increase in drugs used to manage pain

Press Ganey/ HCAHPS
https://www.pressganey.com/solutions/service-a-to-z/hcahps-regulatory-survey
HCAHPS (Hospital Consumer Assessment of Healthcare Providers and Systems) is your basic patient satisfaction survey. Now what the problem with this is that Medicare decided to tie 25% of their reimbursements to patient satisfaction. This is a terrible idea. Studies show that higher patient satisfaction is tied to worse patient outcomes and increased cost. Now imagine that you're working in the ER and someone comes in saying that they are in pain. If you don't think they need narcotics they may get angry, and give you a poor rating. This will decrease your take home pay for acting responsibly. If that patient ends up in the ER multiple times, they will get more surveys and the more it can affect take home pay. Also hospitals will pressure their doctors to improve their scores because it affects the hospital's income.

I don't think that this is right, but there are many doctors who start to cater to patients as customers and try to increase satisfaction instead of doing what is right for a patient.