His popularity stemmed mainly from his ending of the frequent civil wars of the previous century. I don’t recall saying that “the people must have approved of the actions he took.” Can you point me to the specific part of the video you’re referencing?
Not only did Augustus end the civil wars, but he brought enormous booty to Rome from Egypt and elsewhere. Who needs republicanism when you can have free goodies? Not for nothing did Tacitus consider his contemporaries degenerate.