Can/should a doctor's office create separate GMB accounts for each doctor?
Each doctor is allowed their own business profile in addition to the primary office listing.
The main office would be called the practice listing, and the individual listings are called the practitioner listings is the terminology that Google uses.
Practitioner listings allow for a different primary category than the practice listing. This provides more keyword coverage for those specific types of practices.
A downside of having practitioner listings is splitting user reviews amongst different listings. Also, if the doctor controls the business profile and leaves the practice, the doctor will most likely take their profile to their new location and all their reviews.
You can find more information on Google here.