Hold on. Russia went from invading a neighbouring country less then 5% its own size on 4 fronts, which we all deemed plausible and likely a success within weeks, if not days, to being relegated to engaging in artillery warfare like it's 1922 over a fraction of the initial front line and territory it was 5 months ago. Ukraine who has a fraction of the armed forces and materiel are receiving materiel, yes, but they are unfamiliar with it nor did they have had time training with it.
Russia went through its supply of modern materiel in the first weeks of the war and is fielding old tech and are only able to keep some momentum because of said artillery warfare, because it's both ruthless and destructive as well as low in technical requirements. They are in addition having to reconfigure their economy for total war over what is a fraction of a far smaller neighbouring country which was utterly unprepared and one of Europe's poorest.
The West sending some of it's military surplus is far from doing everything they can.
Russia having some minor gains recently is very much a matter of winning the battle but not the war. The only way they keep that up is total self destruction, which is not winning.