If you want to setup an account on your system that will be used only to transfer files (and not to ssh to the system), you should setup SFTP Chroot Jail as explained in this article.
In a typical sftp scenario (when chroot sftp is not setup), if you use sftp, you can see root’s file as shown below.
SFTP is a protocol that allows for the secure transfer of files over a network. It is often used by businesses and individuals to transfer sensitive data.