America didn't change, probably because we have been so geographically isolated (relatively speaking), whereas the modern day UK did change to be more like Europe.

People get so goddamn hot and bothered by things that ultimately don't matter almost like it is a culture war issue. Americans maintain the mm/dd/yyyy format because that's how speak the dates.

I wouldn't say it is us Americans who "find it hard to read" if someone from elsewhere in the world sees an American date, knows we date things in the old way they used to date things, and then loses their minds over having to swap day for month. Everyone just wants to be contrarian and circle jerk about ISO and such.

Us devs, on the other hand, absolutely should use the same format of yyyy-mm-dd plus time and time zone offset, as needed. There's no reason, in this age, for dates to be culturally distinct in the tech space. Follow a machine-first standard and then convert just like we do with all other localizatons.

But hey, if people want to be pedantic, let's talk about archaic gendered languages which are completely useless and has almost zero consistency.