Why have more than one FTP account?
Having more than one FTP account is useful for giving access to only a portion of the hosting files, so there are directories that not all personnel can access.
For example, if the same hosting has more than one website in different directories, which are developed by different teams, you can create an FTP account for each directory, and each team will have the FTP account corresponding to the directory of the website they develop, without being able to modify the other team's.