Command to get a CSV from a GeoPackage:
ogr2ogr -f "CSV" FILE.csv FILE.gpkg -sql "SELECT person_id, trip_index, departure_time, arrival_time, mode, preceding_purpose, following_purpose, ST_X(ST_StartPoint(geom)) as 'x0', ST_Y(ST_StartPoint(geom)) as 'y0', ST_X(ST_EndPoint(geom)) as 'x1', ST_Y(ST_EndPoint(geom)) as 'y1' FROM FILE