Seems to me it's insurance that dictates what is prescribed. When it was discovered that I had an irregular heartbeat, first thing I asked was, am I going to need a pacemaker? No. the doctor said, we will try to control it with medication first. Well, the medication didn't help. Then I had an assistive device implanted. It appears that insurance either encourages or mandates that this least invasive -- and least expensive -- treatment is tried first. If that doesn't work, then go for the more expensive.
Same with my diabetes meds. I was taking one drug that did a good job, but then the formulary used by insurance companies changed and that drug was given a higher tier -- which meant a higher copay. Doctor switched me to a cheaper drug that didn't work well at all. I had to fight tooth and nail to get back on the more expensive drug. Doctor kept going on about the higher copay, but I told him I'll pay more for a drug that works.
Maybe it's because my insurance is a Medicare supplement, but I'm not getting the most expensive drugs or procedures. After all, we old folks are going to die anyway. If the cheaper med or treatment doesn't work and the patient croaks, who cares?