As you say, attrition war means everyone loses, no matter how it ends. What a bloody if realistic analysis. Wars are very good for killing lots of people and destroying civilisation infrastructure. They are good for demonstrating human folly and hate. If Russia decided to withdraw, still the USA also loses because Ukraine as a war ravaged nation will have no means of paying back for weapons and resources debts. Europe and NATO are in economic decline. Russia won’t pay. Russia won’t collapse soon. There is no way Ukraine can be defended long term by the collapsing west without first a complete annihilation of Russian logistics., war making capacity. The Russians don’t need to be very competent, just to maintain an indecent kill ratio, and invite more Ukrainians into the slaughter zones.
The notion that Ukrainian resources and assets taken over by western corporations as loot, will be both safe and productive later is just too stupid when they will always be under the shadow of Russia, which has made its point, that it could still chose to invade again anytime, unless it gets a satisfactory long term settlement. The west keeps playing the corporate resource territory acquisition game, like as if empire still works, but fails every time to do the hold keep and manage part.
So far the USA is waiting for Ukraine to collapse as if it will be fresh emotive-reason excuse for all out global nuclear ICBM war, required for global economic collapse, and human species extermination. Goodbye homo stupids.