Hi, @tao
Thanks for the clarification. The channel delete feature is available for administrators who have access to the command line backend of the server deploying Mattermost. In this case, you should still have some sort of control on who can delete channels by limiting users who have this access.
Specific to chat history deletion, the feature to allow who is able to delete them was originally introduced to Mattermost but it was eventually removed in June 2018 as mentioned in the Allow which users to delete messages documentation.
Perhaps we can consider opening a new feature request to bring the feature back - EE: Message Editing & Deletion configure option.