There is a good thread about image metadata here: https://forums.puri.sm/t/image-metadata-security/22544.
As others have pointed out, Metadata Cleaner (https://apps.gnome.org/MetadataCleaner/) is a good GUI option and is adaptive to the Librem 5’s screen. It’s really easy to use. I haven’t tried exiv2 so I can’t tell you how it compares with the amount of data each tool removes.