The problem here is not the doctors. It is billing it to government insurance. Doctors should remain free to gratify patients who are willing to pay cash rather than bill to government insurance. In fact, most such gratifications never have a problem for precisely this reason.
It's still partially a problem with crooked doctors.
This is just a step adjacent to the online pill mills for ED medication, GLP-1s, and ketamine, only the advertising and service delivery has been adapted to the elderly that don't use the Internet.
Instead of ads online it's ads on daytime television bragging for free orthopedic supports and braces at no charge to you if you "call today" while they link you up to someone that signs a prefilled script for fifty bucks a pop to bill out to Medicare.