There isn't going to be any specialties that disappear or are overrun by midlevel providers, physicians will always be more desirable. In my opinion, basing a career choice on speculation isn't wise. If you truly enjoy a specialty, don't avoid it because you're uncertain of how the future will impact that specialty.
Yes and no, yes to a degree (Physician specialists do adapt) but also in large part "no" because physicians arent in control as to what they do, where, when, nor why.
Medicine is a business. Physicians need to embrace this joyfully. Otherwise, the lashings will continue. Every large established business has a business plan that uses metrics to decide how to turn a profit. Regardless if CMS, 3rd party payers or private cash is floating the business, a health care facility will not run gratis. Physicians will not work gratis. As long as a sector / department is contributing in the positive to the overall business plan, then they are retained. If they are a cost, then they will be eliminated unless if their existence is essential to the overall business in spite of it being a cost, e.g. a hospital must have an ER, an OR, an ICU. They may merely exist but will not be eliminated. Few hospitals offer Level 1 Trauma Centers for a reason. Some hospitals have minimal number of OR rooms while others depend on 30+ suites in OR for their revenue.
e.g. Today interventional cardiologists are a dime a dozen. Hospital billboards litter the nation with promotional efforts of their having the #1 stroke / heart center. Not so 20 years ago. Cardiothoracic Surgeons were the top dogs through the 1990s. Then along came the bare metal stent. The CT surgeons complained about the CDs suddenly having new skillsets / toys. The CDs adapted. Now they both coexist. However, the CT surgeon was at one time practically revered while the CD was "meh" in the eyes of CT surgery (NB: I worked as a clinical perfusionist team member for 9 years). The same applies to oncology: cancer centers 30 years ago were largely morgues. Today not many hospitals can afford to operate a state of the art cancer center even if there exists a need (supply/demand) but one can find multiple cancer centers in one major city. Again, the oncologists had to adapt - new toys (targeted therapies). Ditto for Infectious Diseases 40 years ago. The ID physicians then were a rare find. Their work was largely limited to nosocomial infections unless if they were situated in a major city with much travel (NYC, San Francisco, etc) and they addressed the rare bug that entered from travelers. Then came AIDS in the 90s, and the ID physicians exploded in their importance, i.e. they adapted. Today HIV/AIDS is treated by GP, FP, IM physicians because they too had to adapt. Meanwhile ID physicians lost prominence. So they adapted to "global health initiatives", chase bugs across the globe. In my state university hospital, the ID physicians are essentially HIV /Hep docs. We don't have much travel to our region, and nosocomial infections are just that.
Depending on the region of the country, certain areas of medicine can thrive while others are not offered in great numbers. So the physician must go where ever the business is certain. Since the business leaders have to turn a profit, if the jobs can be done by skilled workers at a lower cost, then the higher paying jobs will be reduced in number or eliminated. Ask Anesthesiologists what Nurse Anesthetists have done to their profession. They are losing in State Legislatures across the country. Physicians beware. Learn from the plight of the Anesthesiologists. Adapt or be reduced.
We see this at pharmacies. At one time a pharmacy was largely staffed by multiple Pharmacists. Not so today. Pharmacy techs are mainly running the business while 1 pharmacist does most of the "official" dispensing.
As long as the current business model reigns (third party payers),
physicians should think like business professionals. Since a business is run at a 30,000 feet level, those on the ground won't notice the changes that need to be done as to business direction. However, the business leaders see the horizon all too well. If an NP or PA can do what an MD can, the business has no reason to employ the MD. Thus the MD should continually be justifying their existence, developing their skills and promoting themselves as invaluable to the overall health care industry. Their brandishing their MD Degree is laughable b/c it doesn't work in the business model. Evolve or become extinct. Given that physicians largely are complaining, moaning, whining and not playing ball with the business / hospital admins (like this thread), they are losing their shirts....literally. First came their salaries, then came their titles, slowly their job descriptions exploded to which brings us to the current discussion
TL;DR: If you don't like the threat of NP/PAs encroaching on what a physician can do, when, where and why, then you need to play ball with the hospital / business leaders. Otherwise offer your own competing medical business paradigm. I vote for the latter.
Happy selling