There are exemptions for academic research and journalism in the GDPR under article 85 [0]. That is why the original news article (that I wrote) clearly mentions right away that the information was collected for a academic project.
I don't think that many stores track customers and that a lot of the hype from a couple of years ago never ended up in a successful commercialization of the technology.
Disqus does not track users from GDPR countries by default. My initial story in December 2019 for the Norwegian broadcaster NRK was a result of Disqus not knowing Norway had the GDPR (we are part of EEA, but not EU).
Users are checked based on IP whether they come from a GDPR country. If GDPR, they will be put in private mode. A user needs to create a profile and consent to sharing for tracking to begin.
Norwegian DPA opened an investigation as a result of our stories and Norwegians are now in private mode by default.
[0] https://bookdown.org/fede_caruso/bookdown/the-journalistic-e...