And leave Russia with the "land bridge" to Crimea? Putin will negotiate in good faith and end his aggression for real this time?
While most of the people who could leave the east in 2014 did leave, that region is Ukraine's industrial heartland- that's your iron ore and gas deposits, the steel mills and heavy manufacturing, etc. Plus the Azov and Black Sea ports. Odessa would always be under threat.
I don't think now is the time to make concessions. Ukraine just delivered to Russia the worst battlefield defeat since WW2. The 1st GTA has been effectively removed from the Russian OOB, fully 50% of the 4th GTD (the most "elite" tank unit) is destroyed. The 6th CAA is scattered to the wind, and the Western Military District has their 3rd Commanding General in a month. The 49th CAA is trapped in Kherson, and all of Kherson Oblast is under UA fire control.
Finish the job. Force the surrender of the 49th, push from Zaporizhzhia to Melitipol and cut the Russian occupation in two pieces. Then see how Putin feels about Ukraine after losing 2 armies and having his Black Sea Fleet at risk.