America is the land of prudes. We still haven't overcome our Puritan foundation.
You know why you can't buy alcohol on Sunday? Because it's the Lord's day, man.
You shouldn't be drinking; you should be in church! Really. No joke.
It comes from a law written in the 1600s. And we still enforce it in 2020.
The nipple issue is similar. I've been around the world and in almost every place I sojourned nobody gave a single damn about women being topless or wearing clothes so light and sheer they were basically topless. The only people other than Americans to get so wound up about nipples are Islamic countries. Nobody else cares.
Personal experience: Once you are surrounded by topless or even naked women for a few hours or days, you go into 'doctor mode'. That is, you don't really notice it or even care that much anymore. You get so used to it that it becomes normal - no big deal.
But America is kind of 'nuts' about nipples. I've watched movies with people being tortured, beheaded, disemboweled, whatever, and that is perfectly acceptable. The only caveat is, while you are torturing, disemboweling, and beheading the woman, make sure you don't show a nipple. Because that would cross the line. LOL! America. What a country...a country of prudes.