When Data Export enabled in ExB for an app, the user can export a feature data into any one of four file formats, none of which are directly-usable for the average user. GeoJSON comes closest by including geometry in the data, but that format still needs to be converted to a common consumer file format that can be used in popular mapping apps such as OnX, devices like Garmin GPS units, or just to import to other AGOL-based apps through the Add widget.
Exports formatted in GPX and KML (or KMZ, compressed version of KML) are what my users are after.
Yes, users can use a 3rd party converter (some at cost after a few free uses) from GeoJSON to GPX or KML, but that is an extra step which users should not have to face.
Common consumer map app services such as OnX and Gaia give users the tools to export their tracks and waypoints GPX or KML, so users have become accustomed to this capability and wish it were just clicks away as in their other favorite mapping apps.
From Idaho Trail app at https://arcg.is/0ivqPS
While one of our community members has come up with a way to create custom tool for this, I would hope to see this built into ExB in a straight-forward way.
See https://community.esri.com/t5/arcgis-storymaps-questions/export-features-to-gpx-files/td-p/639714