That is only because WE had rules of engagement that prevented actually defeating the enemy.
The russians may be blundering fools on the battlefield but they are ruthless and have no such obstacles as rules of engagement.
Putin is probably railing about attacking the convoys, but his generals mouths are dropping to the floor at the idea of war with NATO when they can’t even finish Ukraine.
The Russians are fighting like they always have, which involves making many mistakes while also being utterly ruthless.