People should not try to be their own doctors, like they should not try to be their own lawyers. Your self-interest will work against your objectivity, most likely to your detriment.
And only 20% of Americans get an annual physical.
So, yes, if you can afford both the the time and money to seek proactive, possibly concierge medical advice from a professional, choose it.
Doctors are similarly limited by your advice. If you want to eat healthy, a dietician will be able to offer much more specific and actionable advice. If you want to gain mobility, muscle, and health span, a physical therapist, physical trainer, or yoga instructor is who you want to see.
Financially, we're at a point where blood and urine tests can be taken at home for a fraction of the cost of a single health care professional visit, boosting sample rates and ability to react (including talking to a doctor)
There are certain preventive care services which are justified by evidence-based medicine criteria on an annual (or other periodic) basis. But those aren't what most people think of as a "physical".
https://www.healthcare.gov/coverage/preventive-care-benefits...
Being able to read and understand legal text helps you in common areas like agreeing to terms when signing up for cable.
Be your own lawyer or doctor but accept the level of skill and education you currently have and call one when you are over your head.
but are we experts at choosing experts?
life is such is that we have to muddle through when we barely know anything
live or die by your own choices you got only this one
Most doctors would tell you they would love it if patients advocated for their own health. Most of the time they deal with patients who are barely interested in their health.
Anecdata, my mother's cancer diagnosis (which she passed from a year later) took longer than it should have because her general physician was a piece of crap and kept insisting it was just bad constipation.
Take a first, second, third, whatever opinion always. And best not to show previous diagnosis reports to the next guy, as that tends to bias them.
Had a "reputed" doctor-professor at an Indian medical school who barely looked at my endoscopy and colonoscopy reports and insisted I was simply suffering from stress and diet issues, when it was actually the signs of Crohn's disease, which was correctly diagnosed by NHS doctors.
(And as someone with a rare incurable disease, I had no choice but to advocate for better tests, second opinions, more information. ALWAYS get a second opinion on major life events, IMO.)