I found an interesting study quoting 400 years of US Military Studies, that claims: "The average advance rate across the Russian front ... is 7.8 km per day – still putting Russia well ahead of pre-1990 historical averages" (this was at the start of the war). 7.8 km per day was well above historic averages of advance against peer forces, suggesting Ukraine's army was not a peer army as the Western media proclaimed, and would likely not have lasted more than a couple of months without western support. https://www.leidensecurityandglobalaffairs.nl/articles/keepi...
NATO weapons slowed the Russian advance down by making Ukraine more of a "peer", at least until the weapons dried up. Now that they have, Russia seems to be steadily and rapidly taking territory back while the West is distracted with Israel and the Houthis.
Ukraine will last as long as the West is willing to give it (expensive) weapons in the middle of an election season. And Russia will gleefully watch us burn taxpayer money while they ensure there is no one left to give those weapons to.