WKT carries geometry only, with no names or properties. GPX is read by practically every GPS device and fitness app. WKT is at home in writing a single geometry in a database or script; GPX is the usual choice for GPS tracks, routes and waypoints.
Every format is read into plain GeoJSON features and written out from there, so coordinates, names and properties carry over wherever the target has a place for them. Each geometry in the file becomes one feature without properties; WKT in a coordinate system other than latitude and longitude is refused. Points become waypoints and lines become tracks; GPX has no areas, so polygon outlines are written as track segments. Elevation and time are kept.