Regardless of if you think the abandoned equipment video is legit or not, one thing stands. Russia being forced to retreat and abandon all attempts at taking or shelling Kiev into submitting is a large blow to the Russian war effort, No matter how Russia frames it. This is huge for Ukrainian morale as they successfully defended Kiev and kicked the Russians to the other side of the Pripyat Marshes and their only foothold west of the Dneiper is Kherson which have had successful Ukrainian counter attacks near it.
Not to mention, Kiev not being taken basically takes regime change is off the table, anyone who thought putting up a puppet government in Kiev wasn't Putin's main objective when the troops first drove into Ukraine is huffing Heavy-Duty Copium.
This war isn't over yet, but morale as well as gaining inititive is a major part of winning a war, and Ukraine just got a big boost in both.