AFAIK, the problem isn't that the doctors CAN'T, it's that they WON'T despite patient demands. And people are falling into Dunning-Kreuger gap all over the place...
It's literally that they can't without being fired.
Most doctors work for a healthcare group of some kind, rather than entirely on their own, these days. Those groups decide what the doctor is allowed to do.
I had a private doctor that got forced into one of these groups before. He was perfectly happy with the group of meds I was on. After he was put in the group he was hyper apologetic to me but said the group forbids him from allowing someone like me to be on those meds and I was forced off them.