I can confirm I had no stalls through school

This was the norm in the UK in the 1980s (my only point of reference as I haven't kept an interest). I can confirm most people didn't really have a problem with it but also that the teacher who supervised spent a few years in prison later on for reasons I can now see were totally related.

No stalls. And if you refuses to strip naked and shower you got detention at my school.

The PE teacher was ALWAYS in the fucking locker room too.

The locker room and the shower room at my high school was also the same room. No partitions no privacy. The showers was just a row of shower heads on the far end of the single big square room.

2010 locker room and shower room were in the same area all open some people changed in the bathroom area if they felt uncomfortable but showers were open

When I was in middle school, we had rows of lockers and a large shower room with multiple shower heads.

I would change from the PE uniform into the school clothes at my lockers, never once did I shower naked in front of all the others. wtf. They had no privacy at all.