LightWave models are made of polygons, so every tool in Modeler will help us create and edit polygonal geometry. We can create anything we want in Modeler, but Modeler cannot read our mind. We must know what we want to model before we start.
Word Processor Program Analogy: "There is no 'Shakespeare' button. Novels are made of words, so every tool in WordProcessor will help us create and edit English sentences. We can write anything we want in WordProcessor, but WordProcessor cannot read our mind. We must know what we want to write before we start."
Note: That said, LightWave has some tools that can instantly create a specific object. Construct > Utility > Additional > Teapot, for example, makes the cutest little teapot.