Setting up additional users will come in handy in the case as with an additional FTP user, but in this case the user is created to be able to access the control panel. There are different situations when it is necessary to transfer access to the panel, but with limited capabilities, for example, for working with databases or accessing only certain functions of the control panel. For example, the developers made a site at their booth and are ready to transfer it to your hosting, in this case it will be convenient to create another user and assign him a role (access rights).
A user is created and a role is assigned to it, for example, Application User, in the case when you have several sites, you select the site to which you want to provide access and tick the active user to allow access to the control panel. Another advantage is when several people work on the site and you do not want to give your username and password for security purposes, for this create a new user, assign him a role.