Us old timers that started in COBOL know that your leading zeros rant isn’t really justified if you think it is someone’s intentional design decision. Rather it is from a requirement of the language of the time. When I see a company that is using numbers that begin with leading zeros I know that company system started out in COBOL. May very well still be using COBOL. COBOL didn’t have the dynamic sizing of our current day languages. We had to define a field to the largest character count it should hopefully never get too. A new record then filled that field. Since numbers are right aligned you are padding zeros up front.