Earlier quoted context omitted.
This was the finding of the case Patrick Breyer vs Germany in 2016 https://www.whitecase.com/publications/alert/court-confirms-... What makes a dynamic IP address personal data? The CJEU decided that a dynamic IP address will be personal data in the hands of a website operator if: there is another party (such as an ISP) that can link the dynamic IP address to the identity of an individual; and the website operator ha…
From your cite: >Where a piece of information (such as an IP address) does not directly identify a person, that piece of information will nevertheless be personal data in the hands of any party that can lawfully obtain sufficient additional data to link the information to a person's real world identity In a world of data brokers that makes IP addresses PII. The only way it's not is if you verify that there is no way…
You can see why people err on the side of caution.