There are two paths to compliance with GDPR.
Option 1: Accept that you're collecting Personal Data, and satisfy the obligations GDPR places on that. This means disclosing the use of analytics in your privacy policy (what data's being collected & why), listing retention periods, and figuring out how to satisfy requests like Access or Deletion (which may include "we can't identify you in the data we previously collected).
Option 2 is to "comply" with GDPR by finding a loophole that it technically doesn't count.
The Option 2 approach is more common when dealing with American data privacy laws. It doesn't work out so well with GDPR. It's very difficult to not be processing personal data at some point. Even if you fully anonymize your data before doing any non-trivial processing, the anonymization itself is still covered by GDPR. Which means you need to include it your privacy policy and provide opt-out.
It's also high-risk. If a court decides that you didn't quite thread the needle through the loophole in their country and GDPR therefore applies in full, then you haven't done any of the compliance groundwork.
For GDPR compliance, I would be much more inclined to trust a tool that describes how to opt users out of tracking than one that claims they're immune from obligations to opt-out.
As another commenter mentions, the ePrivacy Directive is a whole different kettle of fish. Strong consent needed to read or write any data not strictly necessary to provide the services requested by the user. That law should get updated with more sanity soon... it's been that way for a few years now.