A friend with a life time in cycling shares your opinion. He has done road, track, MTB for many decades. Even won his category in the Trans Baviaans. He just laughs when we talk of bike fitters. At mid 60's he does one off 100km ride every 4 to 6 weeks, and a couple of 30 to 50km rides per week. He just did a 6 week training block to prepare for the 36one. Testimony of what is possible.
And here is the rub .... @DieselnDust as an engineer you often experience the difference between "good" and other engineers ..... Sure your wife has experiences with some "good" doctors and a some others .... it is the reality of any industry.
The bike fitter industry is no different. Many (possibly most) are good at taking measurements and setting up a bike to a formula ..... and this works well enough for those riders with no residual medical/injury issues.
The likes of Irma does what I need from a bike fitter. Starting with a medical/injury history. Then checking mobility, core strength, flexibility .... Only then does the "bike fit' / adjustments" start. And when the client has specific issues, the setup is most certainly off the "standard charts" and tweaked to that individual. She also explains that as issues are addressed, your body adapts small setup tweaks may be needed.
LUCKY are those that are injury free and for whom the "dimension chart" type setup works.
Now to take this one step further ......
I have done about 10 000km on my "Argus bike" over the last few years. Setup fine, no issues. End of last year I suddenly start having issues .... Seems like the Selle Italia saddly had sagged out. Bit of a search, but I find the exact same saddle. Bike setup measured up with a laser level ... yea yea ... So I carry over the setup 100% to the new saddle. NOPE !! I cant cycle 5km !! Two other saddles later I went back to Irma .... we swopped out a number of saddles, checked and re-checked the setup, just cant get comfortable on the bike. Irma steps back, head tilted to the side .... and then she gets a frown ..... "When last did we check your sit-bones?"
Let me tell you .... in that moment that question did not make any sense ..... but let's check it again.
Turns out my sit-bones allignment was out by more than 10mm ! Basically one sit-bone at a time could sit correctly on the saddle .... no wonder it was so painful.
Here is the shocker .... this is not an uncommon issue. She referred me to a physio, who confirmed my left QL was one tight spasm ..... took about 3 physio sessions to remedy my allignment. Few more bio sessions to get to the root cause.
Moral of the story ..... IF you have some history with sports injuries and are on a road of recovery. Expect your body to change as you cycle/exercise more. These changes may impact how you "feel" on the bike.
TOP TIP - STAY IN SHAPE. Use it or loose it !!!!! The road to recovery sucks .....