Not being able to take the territory, having a ceasefire over the territory, and actually conceding the territory are three different things. The world is full of unceded occupied areas. Korea. Taiwan. Northern Cyprus. Palestine. Nagorno-Karabakh. Transnistria.

Ukraine rightly has no interest in ceding land to achieve a temporary ceasefire to allow Russia to re-arm and then attack again.

Meanwhile it is also important that we don't have two nuclear armed states (France and Russsia) officially at war.

>The war is at a complete standstill and it will last for another horrible decade if no concessions are made.

There is a slight hope that the current Russian regime will collapse before then and be replaced by one that doesn't want to continue the war. (Though, that said, it could equally well be replaced by a regime that's even more ultranationalist than the current one.)

While Europe certainly does lack the political will to make a substantial intervention, it's not just a question of political will. There is the small matter of not starting the third world war to consider.