Saving lives is the reward.
How?
First, Putin has stated that Ukraine has no right to exist. How does splitting Ukraine into two states change that?
Second, there is no social division between eastern and western Ukraine that suggests splitting the country in two. Where would you draw the border? At the Dniepro? What's your justification for putting Kharkiv with the Donbas rather than Kyiv? You can state the language division, but language isn't necessarily what builds unity or identity, or the inverse. It's too simplistic, especially since everything that's happening to Ukraine is currently drawing its regions much closer together.
Third, where does this put the Donbas anyway? Are you suggesting a division into three? (west, east, Donbas) Or are you putting the Donbas with the east? If so, are you expecting Russia to agree to let go of the Donbas so it can join the new country of East Ukraine?
Fourth, if all the works, why would anyone expect Russia to leave the country alone, and not attack and conquer East Ukraine first, and West Ukraine a few years after?
Finally, it's all very nice to blame people for confusing loyalty to their country with loyalty to their govenrment, but how does splitting up the
country fix that?
I just don't see how what you're proposing solves anything. It seems like something random you'd impose upon Ukraine, akin to how European colonial powers carved up Africa and the Middle East. I don't think anyone would call that a success story.