Exactly. Saying otherwise is classic straw man.

I don't know much about Costello's early years, but I believe he rose up the ranks for no other reason than he was liked by Luciano and other key leaders. Luciano was primarily interested in making money and surrounded himself with men who were good at it. Costello probably had the business smarts and skill set for keeping the peace and running things smoothly. I question if he was even feared by others prior to becoming boss, but he would be feared after getting into that position.