You've probably agreed to that somewhere in the Terms Of Service and therfore gave consent
According to https://gdpr-info.eu/issues/consent/
> Consent must be freely given, specific, informed and unambiguous. In order to obtain freely given consent, it must be given on a voluntary basis. The element “free” implies a real choice by the data subject. Any element of inappropriate pressure or influence which could affect the outcome of that choice renders the consent invalid.
Declining terms of service will affect the outcome so it can't be considered "freely given consent".