While equipment is a slight upgrade on the Russians, I think the key factor here is command leadership as the Russian side has had some AWFUL commanders, just downright stupid and bullheaded leadership that what could have easily turned an initial entrapment and pincer movement into a long drawn out stalemate.

It's why the wagner group is humiliating them more with their successes since their leader at least knows how to apply misinformation to bait Ukrainian leadership to attack strengthened positions to turn it into a meat grinder and giving time to fortify weaker positions.