A medical certificate should assess little more than whether you have, and are likely to continue to have, the physical capabilities to do whatever you are licensed to do for the validity period of the certificate
Thank you for that, which is as succinct a summary of our role as AME's as I have seen in a very long time ! It's quite true that this is NOT the same as assessing or prolonging longevity.
The OP's reference to "hogwash" leaves me gasping with disbelief ! But my opinion matters not one jot, compared with the millions who make professional pilots' jobs economically viable - ie the world's passengers.
Let the OP go to any major international airport and carry out a representative survey of those about to embark on flights. Let's see what responses he gets from passengers to the suggestion that their pilots' vision had not been ascertained; that they were poorly controlled diabetics, who could go unconscious at any time ; or that they were in AF with poorly controlled hypertension, and therefore liable to have a stroke any time soon.