The thing is the russian MOD and putin have plainly, and explicitly said that they would not occupy ukraine and set up a government, and that they would not pay for any of the damages in the war. The russians have only held the russian speaking areas in ukraine, and there's a good reason for this. The imperial core wanted to russia to fight a occupation style war, similar to how the soviets fought in afghanistan. But the SMO has been conducted completely differently, the russians fight a defensive war, and force the ukrainians to be on the advance. Ukraine cannot win the war in a situation like this.