Russia can’t pay the costs of restoration they don’t have the money, any amountof repayment is goingto be a token value to the true cost. We also learned from WWI, that saddling nations with crushing reparations is bad. The allies also invested in Germany after WWII, the soviets extracted penalties that are still noticeable today.
Countries just don’t go back to normal after wars. There’s even more opportunity for corruption while rebuilding. Entire cities will need rebuilding, “temporary” housing will need to be established, millions of refugees need places to return to that have power, water, and employment opportunities. Figuring out any looting or plundering is basically impossible beyond a token amount.
Rebuilding an apartment complex and replacing all the stuff inside is a long slow process that will need to happen hundreds of times.