The reason
As female artists working under a particular entertainment company, they had a harsher time, being exploited, compared to their male counterparts generally.
There were indeed differences in treatment across the genders and naturally the obligations each party must undertake were different.
The pay gap had been the most argued topic in the modern world. However, the treatment was based on the fan values each artist possessed.
The requirements for the male artist were stringent and highly demanding; so, their incomes appeared higher.
However, the main problem was in a situation the female artist completed everything the same as demanded by the male artist, would their salary and treatment be equal?
In the end, they were still exploited by the capitalists who would try any means necessary to raise their cash inflow and lower the cost, which included the artists' salaries.