ISIS did offer the option of Jizyah to the Yazidis and Christians, but they refused.

Answer

These non-Muslim communities in Iraq had been paying Jizyah for centuries – almost 14 centuries – since the time of the Sahaabah. There is no rational reason why they would refuse to pay Jizyah now and select to be uprooted and killed or exiled from their homes where they lived in peace for centuries. Why would they refuse to pay Jizyah when all other kuffaar forms of taxation would be abolished? We don't accept what you are saying.