I don't think the war will be over until US and EU decide to stop sending weapons to UKR. Now, in terms of UKR prevailing, no matter how you spin it, they lost 20% of their country and the majority of their fighting ability if not for external support. Doesn't look like prevailing to me. Basically any chance they had to be "independent" state are gone, either they are occupied or in heavy debt/reliance to the EU/US.
Yes future looks bleak for Russia indeed, but the same is the outlook for EU. A broken relationship with Russia never worked with Europe historically, and for good reasons. Also, Russia cannot be "helped" from the "west", its not "yet another" country. Whoever I know that has been there, can confirm that its a special place with dynamics that are not entirely understandable by western values.
I don't see China declining, the opposite actually. Yes COVID hit them (which for me screams "Cui bono" to the whole covid thing, but thats off topic) and they are doing bad demographically, but their struggles are not in vacuum. Europe is getting hammered and its even worse demographically, US is in a "esoteric mode" dealing with problems from within.