Only a few centuries after the Byzantines started making this shit up, coronations were now viewed as real and sacred and transformative. Once you were crowned and anointed, you simply were the king – that was the view. Maybe you shouldn’t be the king, but you still were. That’s why, in those days, no one hung about being uncrowned for months so the ceremony could be nicely organized with lots of pageantry. It wasn’t worth the risk of a rival claimant steaming in with some biddable bishop and getting himself crowned while the rightful ruler was busy choosing bunting.