Who decides what is "Formal"? Further, apparently years ago when silks and frilly French fashions were considered "Formal" someone somewhere made a conscious decision to change styles. How did this come about?
No,it wasn't the MODS,it was the hippies,who wanted to destroy everything about the world as it was. Of course,it was the "leaders",most of whom were RED DIAPER BABIES and funded by the KGB,who led the naifs,like so many Pied Pipers, but that's when dressing appropriately, good manners, self responsibility,politeness, and never using inappropriate speech got far more than just a toe in the door.
The "FREE SPEECH" and "FREE LOVE" and "DO YOUR OWN THING " (which was far MORE conformity,than what these barbarians were supposedly railing against!)movements is what changed,upended society.Few fought it then and now, more and more people just accept it all...making the F word ubiquitous,thusly making it a useless word,impolite behavior the norm,and destroying dress codes,so that those who follow this trend are nothing but "proles".
HELLO COMRADES;AS FOR ME,I'LL STAY THE DINOSAUR!