Personal impression:

Everyone knew there was a problem with Oleksandr Syrskyi for a while. How had a tendency to micromanage troops, often causing needless losses by commanding an attack by some unit which was exhausted enough so it could only defend. Maybe a Russian position was taken for a while, but the unit was super exhausted and Russians took it back. This seems to have earned him the nickname “Butcher”.

It also seems that Syrskyi liked to build a hierarchy of command based on personal loyalty, and didn’t like people bringing him bad news or criticism.

Due to his high rank, however, he was immune to criticism from low-ranking people. It took a big dispute with the former defense minister (Myhkailo Fedorov) to bring attention to the problem. This exposed the issue because Fedorov liked to govern by the numbers, and is capable of providing detailed explanations for his actions. He had a reputation of not doing things for personal or whimsical reasons.

A point came when the MoD of Ukraine and the chief of the army could not meet at the same table. When the government resigned, the defense minister was free to explain what he thought about things. So finally there is enough momentum to dislodge Syrskyi, and I think it does them good.

Syrskyi has to go. He is old guard, schooled in Moscow. When you hear about forced conscription, beating recruits, sending troops to their death without a care, that is Syrskyi.