So what's wrong with sanctions as an instrument of attrition?
You are punishing people for rolling poorly on the parental lottery. Some kid starving to death because of sanctions doesn't understand what's happening. Their parents will be too poor and hungry to meaningfully fight back against their leaders. It's only going to hurt the vulnerable people in a country - militaries and oligarchs will not be impacted unless you target them specifically and narrowly . Imagine if China…
If you accept this argument, you are letting the dictator hold his population hostage. Also the same argument applies to killing the invading soldiers.
Also it's not like Russian people are dying from hunger.