When you create an avatar for VRChat, you have free control over when it is deleted, as well as it's private/public cloning permissions.
When using a service like Tafi or ReadyPlayerMe it is not possible to remove these avatars from your account. They just stay there. It would be nice if a user could undo the granted permissions given to these services, as well as delete the content they upload in a similar manner to player uploaded content.