Is any arbitrary imperfect sort not adaquate for roll call? If the full names are sorted naively like any other string, why would that be a problem for teacher

Is any arbitrary imperfect sort not adaquate for roll call? If the full names are sorted naively like any other string, why would that be a problem for teachers? I don't get this. Usually what happens is last names are placed first for sorted lists, but this seems like an arbitrary meaningless convention without real utility. And since this arbitrary convention is problematic in cases where names can take on many forms, it makes sense to disregard the convention. If you're not already accustomed to the convention it doesn't even make rational sense; why should the first name be last and the last name first? That's totally backwards, but it's convention. Why though? It's not even like that ordering will necessarily put siblings next to each other on the sorted list. Many siblings have different last names and many people who aren't siblings have the same last name, so what is the actual purpose of supporting this convention? My name is such a convention-defying name by the way, the way I use it. Often I have to enter "[first initial] [middle name]" as my ''first name'' even though it isn't. Just give me a single name field please. Edit: Annoying example from a minute ago: I gave my first initial/middle name to newegg. Newegg tried to be clever by dropping my middle name and now calls me simply "J." That's not my name!