The problem is that a list of languages has no alphabetical order because different languages use different scripts and there is no standard order of scripts (y

The problem is that a list of languages has no alphabetical order because different languages use different scripts and there is no standard order of scripts (yes there is Unicode, no relying on your users knowing the order of scripts in Unicode is not good UI design). So there is no way to order a list of languages so that someone can binary search them like they would a dictionary. Which comes first: Ελληνικά, العربية, Русский, or 日本語? Flags assist by giving a second piece of information that can be used to identify the right language easier. They still perform this function even if the wrong flag is used. You can scan a list of flags with names faster than you can scan a list of weird unfamiliar language names.