The following are the advantage of SuExec.
1st) To make multiple php processes run under different users for different virtual hosts (vhosts) we can use SuExec.
2)This allows processes to run as your own user, rather than the global web server user like nobody.
3)The advantages are that any files created by your script are owned by your own user, and not a different (web server) user, allowing you to control, remove, add, and edit them via FTP, the control panel, File Manager, web page editor, SSH/shell, etc.
4)If any abuses, spam, attacks, illegal processes, etc. are easier and more immediately tracked and controlled by using SuExec log files.