Not a stupid Isekai protagonist

Most Isekai heroes notice that something is wrong in society. Social injustice, inequality, corruption and abuse of power are everywhere. When they notice it, they try to save the 'damsel in distress' from the evil rich aristocrats. However, they do not want to break an obviously corrupt law to punish them, and the corrupt repeat-offender aristocrat is free to continue to abuse the peasants. NOT ANYMORE. The young hero realises that the only way to save everyone is to fight back, and use their modern knowledge to uproot the corruption and abuse by the wealthy.