What does Vladimir Putin gain from his Tucker Carlson interview?

On Thursday, President Zelensky said he was replacing his top military commander, Gen Valery Zaluzhny, amid rumours of a rift between the two men. That will be music to Mr Putin's ears - his ultimate goal, short of the military conquest of Ukraine, is the removal of the Zelensky government in order to replace it with a pro-Russian one under his control.