Misconceptions in films set in the past

It occurred to me while watching "The Public Eye" the other night that you very rarely hear the Coil-Curl Merger https://en.wikipedia.org/wiki/Rhoticity_in_English#Up-gliding_NURSE in the speech of New Yorkers in films set in the early/mid 20th century when, as I understand it, it would have been extremely common.
I'd assume it's due to its having been disparaged and parodied for so long that it would be difficult for modern audiences to take characters speaking like that seriously.
It seems a shame to me because - apart from it being more historically accurate - I quite like it and would enjoy watching a period film featuring characters just naturally talking in that way.

i think they have trouble with the sex thing and the different standards

One that I heard was started by "Gone with the Wind" was how corsets were laced. The entire scene where Scarlett hangs onto a bedpost while Mammy laces her in so tight that she gets a 17 inch waist is a total crock. Women in the Victorian Era did not lace themselves up like that at all! Nor did they all try to get a 17 inch waist because frankly, for most women it was not possible. Most Victorian women in real life would have to lace their own corsets up (not everyone had a maid or family member to help), and usually they just made sure it was snug and secure, not so tight they couldn't breathe and were ready to pass out. Many women had to wear corsets while working, and it didn't make sense to lace them so tightly.

In fact, a lot of myths about corsets were made up by Hollyweird, leading a lot of dumbass feminists into hating them as much as they did the bra back in the 1960s. A favorite trope of "ye olde Victorian times" films portray "feminist" women ditching the corset as fast as possible and wearing men's clothes to look "badass." Women didn't actually think that way back then.