Personal data is data that relates to to you. What relates to you is the list of users who viewed your profile.

I think it's very close to C-579/21 which was about audit logs. In that one CJEU ruled that audit logs are personal data of you and the person who performed the action. They did allow censoring the person's name in that case (and exact timestamp), but given that in this case LI is selling this information to same person then "protecting others" rings pretty hollow.

Lots of things are like that. A list of things you have bought. Well, the things themselves are not personal data. The relationship is.