To clarify, the GDPR requires that there be a process of account deletion. That process can be a request and manual deletion, or it can be an automated (self implemented) process. That former is possible by user request and you delete the user from WP.
However, you can implement a more elegant self deletion process with the following code snippet, which will add an account delete process to the [wpmem_profile] shortcode:
https://rocketgeek.com/code-snippets/allow-users-to-delete-account-with-confirmation-message/
Yes you are right, formally the user can send a mail to the admin and the admin must delete the account.
To achieve the objective without manual operation it is necessary a link can automatically delete the account.
Many thanks for the useful snippet. Great work!