sudoedit opens the editor as your user and just writes the file as root. For a single user who is also admin on the system this does not matter in many cases.
In a multi user context you can easily escape your editor and run a shell which allows a non admin user to escalate their privileges. So from a security implementation standpoint this must exist and it does for this reason.
Of course this also prevents some mistakes from happening and a bad plugin cannot destroy your whole system easily and so on. It boils down to good practice.