It's just easier for people to see a tick and recognize the bla@bla than it is for them to remember this: npub17e6l6tp789hwwnugm3l6zmgfffh369lv08yfuwj452hflhc530xq36epc7.

Once wider adoption happens, it will also help organizations verify that it is indeed them by having NIP-05 off their own domain (e.g. Google could be google@google.com)

Anyone could generate something that looks like npub17google789hwwnugm3l6zmgfffh369lv08yfuwj452hflhc530xq36epc7