The advantage of an organizations account is that backups are shared. All organization owners and admins can create backups for any repository owned by the organization or can access and restore existing backups.
GitHub organization owners and admin roles are managed in your GitHub account settings for your organization. You can read more about user roles in GitHub over here.
Shared backups are particularly useful, if you are using BackHub as an archive for your inactive repositories and a team member needs a repository that has been archived by another team member. Also in case a team member who has created backups leaves the company, backups will remain in your organizations account.