That has recently turned around. The Czechs have found a million shells for the Ukrainians, and that has freed up Ukrainian stockpiles for immediate use. Assumably the shells that the Czechs have purchased are going to arrive soon and replace the stockpiles.
The Europeans say this is good practice for if trump is elected. trump could completely cut off money to Ukraine, and the Europeans could replace all the money (and more difficultly the weapons that money buys) by midway through 2025. That would leave some difficult months of half rations, but probably not collapse Ukraine.
There is one major problem with that plan. The USA has most of the targeting expertise, and equipment that Ukraine depends on. It costs the USA almost nothing to use, but it could be cutoff by trump. That would require a huge investment in things like satellites, and maybe a decade to replace.
trump may yet be able to save Putin.