TSV is less widely recognised by double-click than CSV or XLSX. GeoJSON is plain JSON that web maps and GIS software read directly. TSV is at home in tabular data whose values contain commas; GeoJSON is the usual choice for points, lines and areas on the web.
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. The first row must name a latitude and a longitude column (lat, latitude, lon, lng, longitude and similar); name, elevation and time columns are recognised, and every other column becomes a property. A row with no valid coordinates stops the conversion and is named. Coordinates are written longitude first, then latitude, as GeoJSON requires. Coordinates outside the latitude and longitude range are refused, since the file is probably in a projected coordinate system.