Corruption has a lot to do with it. Troops not outfitted very well, six years expired MREs, no maps, crappy comms, little conscript training, lied to that they would be seen as liberators, money on paper going into military build-up but in reality into the pockets of corrupt Putin regime oligarchs (as the title says). They have screwed themselves and will now have to resort to Aleppo or Grozhny type mass casualties, and they couldn’t give a damn really.
The Russians also evidently have had big problems with their wheeled vehicles as they used Chinese made tires which were faulty and came apart on the terrain