Why we give ocp in treatment of hirsutism

I wanted to ask that "Why we give ocp in treatment of hirsutism (PCOS MANAGEMENT)why can’t we give only progesterone (as it only decrease LH by negative feedback,also estrogen given in ocp will not increase LH? By positive feedback).

Also why not progesterone only pill given for regularizing cycle for 21 days?

(MY QUESTION IS IN CONTEXT FOR MANAGEMENT OF PCOS.)

Because in progesterone only pills - cycle control is a problem and their is breakthrough bleeding . Leading to their discontinuation after using it for some time

Ocps always have better compliance than pops