Accepting how the world works is not the same as saying it’s moral.
If someone threatens to shoot you, you saying it’s immoral is not a practical defense, unless there is some kind of higher power like a justice system with a police to enforce it. But the entire point of international politics is that such a force does not exist, just countries with interests.
NATO is still a collection of nation states with interests, being powerful does not mean you can be trusted. (As the US has shown multiple times)
The people actually fighting this war, don’t want to, they need to be forcibly conscripted by the Ukrainian government, I have met multiple people that can no longer renew their pasport because the Ukrainian government (and western governments by extension) want them to die at the front.
And finally Ukraine is losing, and probably always was, the economic and manpower difference is just too big. There was a point in the summer of 2022 where Ukraine had a position to get a deal on relatively good terms, and there actually was a peace process going on. But somehow this broke down, I’ve heard rumors that it was the UK or the US that convinced/coerced Zelensky to walk away. I really hope that isn’t true because that would mean they have a lot of blood on their hands, and mostly Ukrainian.