vsedriver said : "In my youth a young lady wouldn’t dream of showing cleavage unless it was at a fancy ball and even then, just a hint… not only have fashions changed, but modestly levels as well I guess."
At different times, different things are in vogue (or modest).
Yeah, if you want to see some REAL Modest women, just go over to Saudi Arabia.
There, a woman is considered NAKED, if any part of her body is seen in public.
And, there, not only is it a custom, but they have REAL Fashion Police, who will arrest any show-ers of body parts.
On the other extreme, is a certain tribe in Africa.
There, a woman wears (essentially) a belt around her waist … with all the rest of her body exposed.
This is modest dressing.
And, if a woman showed herself without that belt, she is immodest.
Swimming suits in the 1930s covered necks, arms, and legs.
If a woman pulled the leg coverings up a bit, that is immodest.
I don’t see society becoming less modest.
I just see that people are happy with what others are wearing (or not wearing).
If not, they would RISE UP and complain (which is easy with the 24-hour news cycles.
If a particular Catholic Church (like the OP’s) would tell its Parishioners to NOT wear certain things to Church (or, for Church pictures), then if a person violated that request, it could be considered immodest behavior.