Blowing up the supply ship at a "safe" dock and damaging other ships that were rafted in place, ready to unload, was a real game changer. Now the dock is blocked by a big, burning ship, further cutting supply lines and lowering morale among true believers in the Russian command structure. The ship will eventually be towed out, but not until munitions stop exploding.
Add to that the cutting of rail supply from Belarus and you've got a lot of troops who know rations will be short, every shot needs to count or they'll run completely out of ammo, and that reinforcements will be a very long time coming. That is not going to contribute to any sense of glory in warfare.
This is the first time Russia has confronted a non tribal country with a strong government and a well trained military and trained citizen mi.litia. They were always going to lose Ukraine, but most people (including me) thought it would be after the military had simply rolled over the country and declared victory. It's beginning to look like Putin won't get his parade.
We didn't factor in the decades of corruption that severely weakened Russia's military. Oh, they could still win in Ukraine if they threw every soldier they've got at them, but that would mean leaving borders unguarded and I know of at least one central Asian republic that would take the opportunity to get some of its ancestral land back.