You attend very different ballets than I ever have. I've not seen any of that in the classical ballets I have gone to.
I find this very hard to believe unless you haven't been to any ballet in at least 50 years.
ALL classical ballet dress the same, unless it is a family-oriented amateur ballet production.
Please provide one photo of a professional classical ballet you have been to in the last 50 years where the dancers were dressed modestly. That I would like to see.