It failed, yes. But it succeeded in great many places, eastern europe, large part of south east asia, some african countries.
Russia is just a sorry ass loser, their country is in downward spiral and needs to exert power over its sphere of influence, thing is that countries in that sphere some time ago decided they dont really want to be aligned. Thus Russia decided to punish Ukraine otherwise the rest will also fall out of sphere (ironically I think they accelerated that process even more).
the point is that many countries through the history surrendered very fast and agreed on whatever aggressor demanded.
> It's not like Russia needs any further territory
that's Putin's wish, he wants to become some historical figure, and people have little choice but follow to meat grinder
In fact it is common knowledge that before 2014 Ukraine and Russia were brotherhood nations. Ukraine couldn't imagine being attacked by Russia, that's why the army was a joke at that time and Putin took over Crimea so easily.