Drawing Bezier curves or paths is going deeper into the vector drawing options of Scribus. Bezier curves have been made popular by the PostScript printing language. We have already manipulated Bezier curves with the Line or Nodes window. But in the former, we didn't have much control on the line, and in the latter we could just modify an existing one. The Insert Bezier Curve tool lets you draw a path with a high level of control. It results in really nice and smooth curves. And if you succeed, there is no need to go into the Nodes window anymore, because most part of the node and control point options can be used directly with this tool while drawing on the page.
Unfortunately, it is at the expense of the complexity and the need for a good practice and foresight. It's feasible, of course, but at the beginning, you will still need the Nodes window to improve your path. Especially because the Scribus Bezier tool is now quite old and would gain from an improvement...