The CIA for the last 4 years has reported that Russia has neither the will nor the capability to capture and hold Ukraine. The only people who are saying it are people like you. Russia will not take all of Ukraine because it does not serve them to do so and it is not militarily feasible for them to do so.
Let’s not forget that Trump was the first president in history to send weapons to Ukraine. All prior presidents including Obama said it was far to provocative to do so.