Just to add another thing, the strategic objectives of Russia are quite clear from the outset, seize the political center of Kyiv, as well as to surround and neutralise the bulk of UAF concentration in the east.People like him keep saying Russia 'lacks a clear strategic objective', but that's just not true, Russia's objective from the start is to seize total political control of Ukraine, for this it requires a full military occupation.
There's no ambiguous objective here, as soon as the Ukrainian will to fight is shown, total war is only way forward. The execution and planning is just extremely flawed/inadequate, causing the objective to be downgraded again and again.
Its not a matter of bad strategy as it is a failure of inadequate preparation and self-assessment. I don't think bad intelligence is responsible for this, everyone under the sun believed that Russia is capable of doing this. The failure is in knowing yourself.