The current ban appeal system is 100% on the forum, meaning that OPs need to make an account just to appeal. Although it is not hard to make a forum account, a lot of people (such as children) have restrictions that prevent them from making one, therefore leaving them no choice but to just not appeal.
My suggestion is to have either a microsoft or google form, which OPs fill out and it forwards it to a discord channel called #appeals. We then have two buttons: a tick or a cross - just like on the reports, so we can either accept or deny it.
Edit: Forgot to add that when you click accept the player is automatically unbanned