The answer is obvious, there was no scenario where Ukraine could have won the war. The only possible thing that could’ve happened was precisely what we see happening. Pretty much anybody with even a minimal understanding of the situation understood this before the war started. Here’s how Obama put it back in 2016

Obama declares Ukraine to be not a core American interest and that he is reluctant to intervene in the country, because Russia will always be able to maintain escalatory dominance there. “The fact is that Ukraine, which is a non-NATO country, is going to be vulnerable to military domination by Russia no matter what we do.”