We (Americans) have certainly become even more puritanical in recent years:

• When I was in Middle School, we were required to take a shower after PE. There was a coach at the showers there to supervise and make sure we took "real" showers. There was another coach at the door to supervise the locker room itself and to make sure we didn't walk out of there without wet hair!
• Showering with shorts on was NOT allowed!
• There were no barriers, no curtains - nothing! The "shower" room had shower heads around the walls, and 2 "towers" with shower heads standing in the center... zero privacy
• In scout camp, when you went to shower, there were 3-5 shower heads lined up along the wall. No curtains, no walls for privacy... there was a fence, but you were totally exposed to anyone else in the showers. (Some of the other Scout camps in Florida didn't even have fencing!)

No one thought anything of it! (Back then, girls were not allowed at Scout camps!)

Years later, in the early 1990s and early 2000s, when I went to high schools as a sports official, everything had changed:

• shower "rooms" had been changed to shower "stalls" with walls between them, and curtains or doors

Even later, as my own children started to attend these schools, it was apparent that the "rules" about showering after PE had changed: my children often came home sweaty & dirty - according to them, virtually no one ever took a shower after PE! (ewwww)

It has been an effort to instill into my children that there is nothing wrong (or sexual) about nudity! Our bodies - ALL OF THEM - are beautiful and natural.

I (and I hope my children) are private, but we are not embarrassed by nudity - our own, or other's...

https://cumception.com/photos/cfnm-vintage-ymca-pool/

It used to be offensive for boys to not be naked while swimming at the Y.

There are even YouTube documentaries on this.

https://www.vocativ.com/culture/fun/fairly-recently-ymca-actually-required-swimmers-nude/index.html