I would not recommend acual deleting it.
Save and delete all your data. Set a new very long password (they allow up to 128 char.).
Then never use it again.
This prevents impersonation. Nobody knows if/when your account nicht be available sometime after deleting it.
Also, if you forget to change your e-mail adress you still have access.
Ich freu mich schon auf den letzten Merz!