Who says God needs to be fair all the time? He does what he does. Period. Yes, he does it to accomplish his purpose, for sure, and God accomplish it through his children and it may, or may not be, "fair".

Up until chapter 3, Ezekiel had been appointed to accomplish God's purpose. And in chapter 4, God told Ezekiel to bear the wickedness and punishment of Israel and Judah. Wow. Seems unfair to me.

But Ezekiel's attitude determined how he chose to obey regardless of the misery of his tasks at hand.

Maybe "unfair" itself is the purpose - to test my attitude and my obedience.

See: Trust and obey