Description - While we have the ability to adjust field sharing and access, we apparently can't report on it like we can with other objects.
Why is this feature important to you - Reporting on object sharing is essential to system administration governance and maintenance, especially when conducting an operational change like reimagining how fields are managed.
How would you like the feature to work - Similar to other objects (like custom forms), add a Shared with as a reportable field for custom fields.
Current behaviour - To overcome the absence of a Shared with field, I have to click into each field—thousands of fields!—to view these settings.