The reason why Ukraine is not called for negotiation along with Russia and USA is Zelensky. Zelensky is delusional, not accepting the ground reality and his only compromise is returning to pre 24th February 2022 condition. It would not be a surprise if Trump sanctions Ukraine until they have an election. There are talks of having a ceasefire for Ukraine to have an election but Zelensky is refusing it to drag the war longer.
No, he understands everything, without him, the rest are practically calling for Ukraine's surrender, which is unacceptable. Zelensky is a tough guy and he's doing the right thing, he's the leader of his country.