Sanctions will not directly hit the target but they will only make innocent people suffer. Ordinary civilians are already suffering because of the war and it will be inhuman if they would let them suffer harder because of sanctions wherein they couldn't avoid. Sanctions could never stop the war or solve conflicts. It will only make the situation worse especially for ordinary people.
Yes, it would be much better if we had an international contingent of rapid reaction forces that, within a few days after the start of aggression, would deliver a devastating retaliatory strike of such force that other potential aggressors would never again want to attack other states militarily. But even in this case, military personnel on both sides would still die and the civilian population would die. You can't do without it.
Sanctions are the minimum that citizens of the whole world must allow so that the echo of the war does not reach them. It is better to sacrifice money and material comforts than to voluntarily or unwittingly participate in hostilities. Those who are outraged by the sanctions proceed from the position that everything is fine for them so far and should be fine in the future. And if not? If the aggressor, after the destruction of one country, goes to your country? After all, Russia is already threatening to attack at least a dozen other states.