Having assessed student by a rubric is always good. Sometimes it is required to get some statistics and/or other information from the individual ratings. For this it would be great to access the rubric ratings for each criteria per student. This can e.g. be a simple export function to retrieve the individual ratings for each criteria.
Similarly ratings may exist in an external application and hence could be imported into Canvas rather than having to manually transfer scores. Note: I imagine a typical canvas workaround would be to not have a single rubric for rating but using multiple assessments to upload individual scores. Not really the same though.