There is a clear definition. There is no overkill, this is required by GDPR.
Article 4:
‘personal data’ means any information relating to an identified or identifiable natural person (‘data subject’); an identifiable natural person is one who can be identified, directly or indirectly, in particular by reference to an identifier such as a name, an identification number, location data, an online identifier or to one or more factors specific to the physical, physiological, genetic, mental, economic, cultural or social identity of that natural person;
and article 15:
The controller shall provide a copy of the personal data undergoing processing