By definition, "Ballroom Dancing", would be, "Moving to the music", in a "Ballroom". (A Ballroom was a large room with a hard wood floor, that was built and used primarially for dancing.)
An old friend who danced in the Big Band error told me that he once danced in a Ballroom with 3,000 other dancers. (Can you even imagine?)
The vast majority of people who have ever dnaced in a real, "Ballroom", were social dancers who were taught to dance by friends and family.
These folks danced for their partners pleasure, and their own. There were no cameras, judges, or mirrors.
The objective was to have a good time, and to meet people.
Wouldn't it be more accurate to call what many dancers do today,--"Competitive Dancing", or maybe, "Sport Dancing"?
I wonder how many young dancers even know what a "Ball" was.