Adding onto this because I just realized that most of the data types/elements that can be deleted using Global Delete apparently are query driven (or can be). However, Attributes are not. I've attached screenshots of the screen when Attributes and Actions are selected to illustrate the difference. The "Include..." box that takes you to a query search disappears when Attributes is selected. IDK if that was intentionally designed that way or a mistake (seems likely to be a mistake since every other type does support queries), but the vast majority of the time that I'm needing to delete a large number of data elements, it has been attributes, so I have bumped up against this limitation many times. (I'd also love to see the expansion of Global Delete, Global Change, and Global Add - all query driven where possible - for things like Relationship Attributes and other "lesser" attribute types.