They are fighting a war they cannot possibly win. Until it's over they cannot join the EU.
They are the most corrupt nation in the region, and the war has not helped. Until they fix that they will not join the EU.
Both NATO and EU have said UA can't join their clubs while at war, so all RU has to do is keep fighting.
The other states within the EU will have a terrible tantrum if the money sink that is now Ukraine joins.
Ukraine currently has nothing but debt to offer the EU, and it is a big debt in terms of what they owe their current "war partners" and in terms of rebuilding.
Other states have been on the waiting list for a long time, and if Ukraine is fast-tracked, they will also have a terrible tantrum.
Lastly, no one knows when the war will end and what the borders will be, so any hints of "join our club" from the EU or NATO until the war is over and the new borders are drawn is at the very best just a carrot to keep the poor of Ukraine fighting the NATO proxy war.
There is little chance that Ukraine as we know it will even survive.