“medical” pot is a joke.
I wonder how often a quack who works for the pot shop says the “patient” needs something else instead of pot??
That’s another thing - the number of conditions that are uniquely helped by cannabis is small. It’s true that it has a long history of medical use - for instance it’s still understood as medicinal in Chinese traditional medicine. But there are substitutes for it even there.
I don’t know the statistics on it, but your mention of pot prescription-mill doctors sounds about right.