I don't have an answer. I think many are doing it for lucrative ad contracts..making themselves stand out from their fellow women athletes.
Why do women wear padded, push up bras with major cleavage showing just going out food shopping?
I don’t know about the cleavage showing but I can testify from experience that it’s hard to find any bras that AREN’T push-ups. Like it’s hard to find dresses that are long enough to cover the necessities when you bend down. Makes me glad I’ve got a sewing machine.