The medical community makes a big deal about the title thing and it’s broadly rooted in attempts by previous generations of physicians to be seen as a respected and legitimate profession. Until well into the early 20th century that was a struggle for physicians, who were often viewed as crack pots that engaged in wild unscientific practices—-because that was true for many. Medical school was a joke at the time by modern standards.
So for all the reasons above when any physician tries to suggest that a physician is the only “real doctor” you can roll your eyes and suggest they crack open a history book and then let them go back to stroking their own ego.
JDs never really went the same path but did take up this odd practice of using “Esquire.” Elsewhere in the world Esq is typically used to formally address young gentlemen without any other title. If your teenage son gets a bank account in the UK their the statements will come addressed to Joe Blogs Esq. To anyone with broader worldwide exposure to titles, this makes the use of the title by lawyers in the US hilarious because it makes the person look like they’re taking the title of some kid in the UK.