Catalog in ArcGIS Desktop allows you to quickly preview a dataset's geometry & attribute table and view specific object attributes using the Identify tool. You can also see native object coordinates without any re-projection or influence of other layers.
Pro requires a dataset to be added to a map before any data can be explored. This immediately adds the complexity of coordinate system & transformation management.
When looking for a particular data in a dataset it becomes a complicated process to add any/all potential feature classes to a map/s and then remove them or the maps if you do not want to corrupt your "Data Management" Pro project.
If this data includes CAD or other un-projected sources it becomes even more complicated.
When previewing a number of features in the same session Catalog keeps the same viewpoint/zoom. Pro Defaults to data extent.