This is not an informed perspective. Anesthesiologists are some of the most highly trained physicians in a hospital.
Human physiology is complicated and on the surface, any job can seem simple if you have no understanding of what is happening. While a large portion of the time, the surgeries go smoothly, sometimes it doesn’t and it can go downhill fast. In that moment, you want an anesthesiologist that can quickly and thoroughly think through a patients medical history, what drugs they’re on at home, the current surgery, variant anatomy, what drugs they’ve given so far, etc to decide on the correct next drug to give or action to take. That takes training and experience.
Physician salaries are a driver, but the far bigger portion lies with insurance’s take, and the administrative costs required to respond to insurance shenanigans.
It calculates US's spending on healthcare to be 87% higher than "Comparable Country Average", and attributes only a 10 percentage point of the price increase to "administration" costs, as opposed the report you linked which estimates 30 percentage points.
Human physiology is complicated and on the surface, any job can seem simple if you have no understanding of what is happening. While a large portion of the time, the surgeries go smoothly, sometimes it doesn’t and it can go downhill fast. In that moment, you want an anesthesiologist that can quickly and thoroughly think through a patients medical history, what drugs they’re on at home, the current surgery, variant anatomy, what drugs they’ve given so far, etc to decide on the correct next drug to give or action to take. That takes training and experience.