I understand but my RuneScape Gold experience let us me think it's fine, if you don't feel comfortable using Qualtrics. So let's say I replied this survey 100% honestly, who would you envision gets that info? After GDPR I have felt so pressured by every single site ever to monitor and monitor me it is disgusting, and even more disgusting that it was all happening before without my understanding. Looking at the survey link along with the basic disclosures at the bottom of the webpage it doesn't appear the Jagex is using a third party fielding company so if the only men and women who would have immediate access to your advice are the survey developers who can pull exports out of the database to disperse internally. EU also has some fairly strong data privacy legislation which (at least my US based company which often interacts with Qualtrics links) are followed pretty strictly by the survey developers and data hosting websites.
After running during the survey Jagex definitely appears to be operating solo on this one. No third party company would allow participants directly enter inside their own contact information (since it would mean they'd lose your business for their customer [so not a nefarious thing]) and also the only area I found kinda strange was the telephone number request in the conclusion. I'd have substituted that using a check box for recontacting and then pipe-in the email that you could optionally have put in earlier for confirmation. I think you are fine answering this survey if you have privacy issues since basically all information is anonymous and it's using an industry-standard platform of Qualtrics. Jagex OSRS Buy Gold probably doesn't have market study ISO certificates but hey this is a quick yearly survey so they wouldn't need to have any. https://www.rsorder.com/