The Russians invaded a huge country with a few troops. This tells you their plan, if you had eyes to see. It is impossible to occupy it with so few men.
The Russians had three objectives in this war. Eliminate nazis, and take the Donbass.
And when peace comes, a non-NATO Ukraine.
They won.
They had no intention of taking large cities, as they did not send enough troops at the start to do that. All that did was keep Ukrainian reinforcements pinned down, and out of the east, where the nazi units are being destroyed. And out of the Donbass which will now be Russian. Forever.
If the Russians took Kiev, they would have to feed it. Of course they don't want to do that. Now the Euros are looking at economic depression due to soaring energy costs, which will destroy their economies. Not harm....destroy.
And Ukraine won't be in NATO.
So now you know.