“Mister” is a maritime title for a midshipman performing a term of endentured service in the navy. Mrs. is the wife of a midshipman. Failing to object to the title of Mr. is another way we fall for their legal trickery. We do not accept titles in America.
You and your fellow Nationals are pulling your etymology out of a hat.
See the Shakespeare’s Merry Wives of Windsor, circa 1600, with the characters Mistress Quickly, Mistress Ford, Mistress Page, none of them the wives of midshipman.
Mister and Mistress derive from Master. Mister was used for skilled men, the gentry, and later naval officers under the rank of captain.
https://www.grammarphobia.com/blog/2017/05/mister.html