I did say minority, to be fair. Female sex offenders do exist. I have personal experience of that, I’m sorry to say.
Of course they’re a minority. Men commit between 90% and 99% of sexual assaults, rapes and child sexual abuse cases.
But this doesn’t mean you ignore them, or don’t treat them. It’s not practical or realistic to suggest that society gets no protection from female sex offenders just because they’re a minority.
My broader point was that chemical castration isn’t a cure-all for sexual predators. It only works on a proportion of men, and it doesn’t work on women at all. It has its uses; but these are not universal.