It also helps that Russia has probably prosecuted the most incompetent offensive war in modern history.
You could probably write a book on how not to fight an offensive war and it would just be examples from this cluster fuck. They did everything, and I mean everything wrong.
They telegraphed their attack, they struck during the marshy spring time, they failed to properly account for Ukrainian command and control elements, lied to their troops and failed to establish proper lines of command and communication, failed to adequately build their supply chains, failed to account fully for western intervention, failed to properly secure their advance and stretched too far too fast, failed to properly ramp up their economy to a wartime footing, failed to properly leverage their soft power, failed to properly train and equip their troops, failed to set up contingency plans in case their “bomb shit and move” strat didn’t work, failed to establish air superiority, failed to contain and suppres partisan activity in occupied territories, failed to adapt their strategy for asymmetrical warfare (Russian bombers bombing empty trenches because they don’t have a procedure in place for assaulting mobile infantry, for example).
The list goes on and on.