What are the benefits of 3D Sketch and when do we have to use it?

Hi friends,

I usually draw my sketches in 2D view and complete the whole shape. What are the uses for 3D sketch? I tested it using splines and I felt it is very hard to control the points. One of those difficulties is non of gumball existence while moving points. The second difficulty is that SW has just a single viewport so controling points is hard. Can someone guide me when and how to use 3D sketch feature especially when I want to use splines?

Does 3D sketch support only surface modeling?

SolidworksParts And Features