The annexed land, land that will never be part of Ukraine again, was the only land Russia prioritized going into the war. It's 42,000 square miles of land that comprised 70-80% of Ukraine's GDP and most of the Black Sea coastline.
For the past year, the Russians have been content to annihilate the Ukrainian army. Ukraine's military and defense lines are now collapsing and the Russian military is making gains daily along the lines of contact.
Ukraine has only two options 1) Surrender, save what's left of Ukraine and agree to remain a neutral country or 2) lose a considerably more amount of territory if not everything.
Right out of Clausewitz, who the Russians read even if our idiots here don't. A key point is "victory consists not only in the occupation of the battlefield, but in the destruction of the enemy's physical and psychic forces."
It isn't about how much territory you hold, but how much of the enemy's ability to fight you have destroyed. Then there is the whole limited war vs total war thing, and Putin is clearly fighting this as a limited war for I would guess the following objectives:
1. Secure Crimea for Russia
2. Secure Russian ethnic areas of Ukraine for Russia [they are also the wealthy parts of Ukraine, an added bonus].
3. Stop the eastern expansion of NATO.
4. Stop, halt, embarass, exeucte, ridicule subvert the golgobalist consipiracy against western culture.
5. Show NATO militaries and their leadership including the CIA/MI-6 and their chohorts up for being the incompotent, scheming, anti-patriotic folks that they are.
6. Weaken the military and economi strenght of the enemies of the Russian state and its people.
So far mission accomplished.