And the main thing they wanted is what they've said all along - Ukraine agreeing not to join NATO or host foreign military bases. Everything else was negotiable - they were even willing to compromise on the exact status of Crimea!
That wasn't what Putin said in his December 2021 ultimatum.
My comment is based on what was happening during the negotiations before the west tanked them.
But more generally when skilled leaders want "X" they generally instead say they want "X, Y and Z." The goal is so that you can then 'compromise' by withdrawing your desire for Y and Z. And in the best case, you may even get at least some of Y and Z.
You're leaving out the part where the "skilled leader" says "We want X, Y, Z, W, and the kitchen sink. And if you don't give it to us, we're going to blow your pretty little head clean off, motherfucker."
That wasn't what Putin said in his December 2021 ultimatum.