I know there are "guidelines" out there for how to handle floating Back to Top buttons, but I haven't found hard data or studies showing that users measurably prefer to use a Back to Top button rather than scroll.

Has anyone done any studies or know of analytics to show proportion of users leveraging Back to Top over scroll?

Asking because in my anecdotal design experience I've only ever added a floating Back to Top button at the insistence of a client without any usability data to back up the requirement. Now I need to introduce another feature that also performs best as a bottom-right floating button (Chat), but I would love to evidence studies demonstrating that Back to Top is worth nixing.