Money spent doesn’t directly translate to capability. Capability doesn’t directly translate to willingness to use it. Russia can spend a fraction and still end up with more weapons and soldiers, resulting in a bigger effective military.
Russia still has nuclear weapons and threatening to use has lead to European leaders hesitating in supporting Ukraine.
Killing Putin and his family isn’t that easy. First you need to know where he is. European intelligence isn’t that great without American support. Remember how lots of Europeans doubted Russia‘s planned invasion right up until it happened. Russia also still has large bunkers and so on left over from the Cold War, where Putin could hide out indefinitely.
Europe doesn’t have unity either. Coordinating will take time and compromises might result in a more cautious reaction to Russian aggression.
Let’s look at a scenario in 2030. Germany has an AfD government and France is run by Front National, in the UK it’s Farage. Russia invades a Baltic country over a fabricated pretext. Poland and Finland react quickly, the Scandinavians fly some air strikes. Germany, UK, France, Hungary, Austria, condemn what’s happening talk about deescalation, and don’t send any military support, maybe even do an arms embargo on the Nordics and Poland in the name of peace. Italy, Spain, and the smaller countries don’t want to risk picking the wrong side and only lament. After a few weeks of righting Russia captures the Baltics and declares a desire for peace and negotiations. Only Poland keeps on fighting Russia by invading Kaliningrad. Poland is sanctioned by the UN and only arms smuggled from Ukraine keep them going. Russia ethnically cleanses the Baltics. Two weeks later Poland ethnically cleanses Kaliningrad of all Russians. Poland and Russia keep fighting a protracted war of attrition for years.