Yet we are very willing to do most of our lifes without consulting any other experts

That just isn't true. Every time you call a plumber or hand your car to an auto mechanic or go to a class, etc. etc. you consult an "other expert".

Reliance on on other people has its own built-in problems -- e.g. the agency issue or deciding which expert to pick (say, you want to lose weight -- there is a large variety of experts all disagreeing with each other...).

your physician assess your physical health

Physicians are rarely interested in or trained to assess physical health. What they do instead is assess lack of disease which is a different thing.