> For a fee of around 30 euros per month, any user can also view the list of visitors to their own profile. However, if LinkedIn is supposed to provide the same information as part of a GDPR data subject access request, it allegedly cannot

A GDPR data request access forces a company to disclose what personal data their hold about you.

It very unclear how a list of visitors to your profile is your personal data. Seems more like personal data of the visitor. Possibly you may argue that the number of visits is your personal data but it seems a stretch to argue that the details of the visitors (what is a paid for service) is.

That being said, when it comes to interpretation of the GDPR anything is possible...