Whether or not increasing a user’s fingerprint (potentially crossing the uniquely-identifiable threshold) is “worth it” is something for the user to decide, not a webmaster. Studies need the consent of all subjects involved, even if researchers believe that it’s in the subjects’ best interests. Users can make informed consent after being informed of the scope of telemetry, how it will be used, and how it will be shared.
A user (like me) who visits a website one time probably doesn’t care if the website “improves their experience” if they don’t intend to re-visit it. They probably wouldn’t consider “collect and share information about your setup, in exchange for a better site in the future” a fair trade. From the perspective of a one-time user, the Reporting API serves only to fingerprint.