Agreed, physicians are definitely capable of giving an IM shot, but rarely do. This may have been a thing a long time ago, but is not done (at least in the US) currently. Source - have been a practicing physician for twenty years.

It’s like starting an IV - the only docs that are good at that are anesthesiologists. They even know how to set up the pumps, mix IV meds, etc. if someone were crashing and needed an IV and infusion started, and I was the only one there to do it, the prognosis would be poor.