The transmission of ip address alone, which is necessary for the TCP request to happen, deanonymizes the request enough to not be considered anonymous within the GDPR framework.
GDPR Article 5 (1) c: "Personal data shall be ... adequate, relevant and limited to what is necessary in relation to the purposes for which they are processed (‘data minimisation’);" - this is the "Datensparsamkeit" you mentioned.
Exceptions from Article 7 do not apply: The user has to give wilfully give informed consent, which he cannot do as the privacy policy of the browser omits the information that all visited domains are transmitted to DDG servers.
GDPR Recital 30 "Natural persons may be associated with online identifiers provided by their devices, applications, tools and protocols, such as internet protocol addresses, cookie identifiers or other identifiers such as radio frequency identification tags."
Oh, and the fact I'm downvoted for a purely informational comment additionally does not shine a good light on DDG.