A Zerg Rush is an early game all in attack using cheap, disposable and fast units with the purpose of causing irreparable damage to your opponents economy BEFORE it can build up.
There's no "Zerg Rushing" 3 years into a conflict. It definitionally won't and can't work. The Zerg Rush was 2022 February. There was a slim chance for success had they been able to capture Hostomel and create an airrbidge into Kyiv, but that failed and the fight automatically turned into what's called a "macro" game. If you want to use Starcraft terminology.