I posted a quotation straight from the recital of the GDPR that says anonymised data does not matter. I even gave a reference that you can look up. The recital even ends with this:
> This Regulation does not therefore concern the processing of such anonymous information, including for statistical or research purposes.
There is no ambiguity here, aggregate data is completely fine as long as I can't trace it back to you with a reasonable amount of effort.
A DPO would disagree with you depending on the circumstance; if you know a user is unique then you have a fingerprint; if you keep that fingerprint forever, when the user comes back to the site, it's trivial to know it is that user.