That was the solution before the people of those regions voted to join Russia. Too many people in those regions have been killed by neo-Nazis and other genocidal racists from western Ukraine. If you don't believe me, ask my friend @MrPwong here on Paint, who is himself a Ukrainian, and has a far greater understanding of both the history of his people and the current conflict than either of us.

Zelinsky holds onto power in his country like a dictator. There were supposed to be elections held in Ukraine quite some time ago, but Zelinsky delayed them using the war with Russia as an excuse, while his thugs go around literally snatching young men from their mothers arms to send them out to die on the battlefield. What we are witnessing is the death of Ukraine, and the only way to prevent this (aside from thermonuclear war) is to make peace with the Russians. That means recognizing the 5 regions as part of Russia, Ukraine not being allowed to join NATO, and the denazification of Ukraine, among other things.
We could go back and forth about this forever, but just watch what happens. Ukraine cannot win this war, and quite frankly, they never could. The only question is whether or not the West is willing to gracefully accept defeat, or whether we would rather risk WWIII just to keep our empire from falling apart.