starving peasants have no money. but long term (like century long) it might be beneficial to pussia anyway. that land area, if they kept it is worth dozens of trillions dollaroos, while they'll spend on the war, lost contracts, lost trust etc. maybe "only" few trillions.  but that's at the cost of quality of life of the current generation russians. but they can take it and always had. not that i suspect putin of being that forward thinking. he does this because of different reasons
Poland