My gym has separate showers but men walk around nude pretty frequently and I haven't noticed any difference based on age. The steam room and sauna usually have men who are nude or in towels but rarely in swimsuits or underwear. The hot tub is about 50-50 nude to textile. Not sure it i a big deal and haven't paid it any attention.
Yesterday was my first experience of a locker room environment for a very long time, about 15 years.
I didn't see nor did I expect to see any towel dancing as I was attending my first naked swim. However, looking round the (female) changing rooms I did notice that it was mostly open plan, with only 2 enclosed cubicles, presumably for the shy people.
As everyone was using the female changing room, I don't know about the male, but I would guess it's the same.
I use a public pool and they now have separate cubicles and yes I was surprised by this especially as others have stated about the sexting craze and the easy availability of nudity online. Haven't noticed any different behaviour though, most guys are mindful of others especially if kids are their with their dad. I leave the cubicle open, rinse off but take my swimmers off and rinse them out, walk back to my clothes where I leave my towel. It is often quiet when I'm there, I avoid busy times to do my lap swimming.
Yes things have definitely changed. I don't think young men are more prudish than earlier but they are more aware of their virtual identity and have grown up in a society where nudity is sexualized. I may be too old to care, but they're not. Still, have hygiene and don't bath in sweaty clothes and basketballs!
I was at a different public pool recently and it was mostly older men as there had just been a water aerobics class. These guys were not bothered about stripping off and walking around to the showers with just their towel and chatting to a friend. So as a stranger there I was comfortable doing the same although I walk around naked in change rooms anyway. One guy younger than me was there but he too was happy to walk around naked but he was about 40. Maybe it's an age thing, we care less as we age.
Again though the showers were cubicles with a door that had a snib type lock.
It really amazes me how people can go in the hot sauna fully clothed. The other day while at the gym I showered and then walked to the sauna naked. The sauna was 190 degrees and the heat enveloping my body felt great and started making me sweat after a few minutes. As I sat there enjoying the heat, my entire body was wet with sweat after 15 minutes when two fully clothed guys entered. I could not believe that they were enjoying the experience with their sneakers, socks, long shorts, and t-shirts on listening to music in their earphones as I sat with them fully naked. As the thermostat hovered around 190 degrees, I looked at them and their clothing made me uncomfortable. I just don't get it.