However, it has never been "the exclusive domain of sex workers".
Most survey results are rather what people are willing to say rather than what happens, and moreso who knows what happened in the past?
It has never been illegal in New Zealand between women and between women and men. It is naturally a matter of personal choice and taste, very intimate, with one less obvious danger for women.
Thankfully politics can stay well out of it, but it is remarkable how it has become de riguer culturally. I can only hope that it is indulged in out of desire and passion rather than a sense of "I'm expected to do this".