Argument from authority is a formal fallacy. But humans rarely use pure deductive reasoning in our lives. When I go to a doctor and ask for their advice with a medical issue, nobody says "ugh look at this argument from authority, you should demand that the doctor show you the reasoning from first principles."

> But humans rarely use pure deductive reasoning in our lives

The sensible ones do.

> nobody says "ugh look at this argument from authority, you should demand that the doctor show you the reasoning from first principles."

I think you're mixing up assertions with arguments. Most people don't care to hear a doctor's arguments and I know many people who have been burned from accepting assertions at face value without a second opinion (especially for serious medical concerns).