Long sentences may easily lose readers, making them ideal for descriptive paragraphs. Long, flowery phrases might assist you in creating the ambiance you desire while describing the location of your novel. A sentence may be thought of as a container for a concept. When explaining a complex notion or concept, you may need a larger container, i.e., a lengthier phrase.  For example, if you're writing an academic paper on cause and effect, it could be better to write the complete idea in one phrase rather than two shorter ones.