M0,0 L100,100 200,200 is one diagonal line, nothing is visually clear. M0.0 L100.0 200,200 will be much clearer - here you will see a triangle.
This happens because when two bezier curves go in a row, the first control point is taken not from the "pen position", but
more details (command "S")
In order not to break the path and start drawing a second bezier curve from the "pen position" you can replace MoveTo with LineTo.