The Purpose of Language
The true purpose of language is to convey meaning. For the author, the struggle is how to embody their thoughts into words that clearly communicate what’s going on in their head. For the reader, it is about being able to take an author’s thoughts, and extract the author’s intended meaning out of it.
If your writing is not clear, then you haven’t done this.
Writing puts meaning into sentences by translating ideas into words. A sentence becomes complex because it holds a complex idea, and the words are BRIMMING with essence and they should stretch to try and convey what it all means.
However, when a sentence becomes deliberately complex just to be complex, but holds little to no meaning, you lose the purpose of that sentence to begin with. Good writers, and professional writers know that every word counts, and every word is put there to deliberately do or convey something.
For example, take a simple sentence like this:
She gripped his sleeve, and murmured, “Stop that.”
and compare it to this:
She gripped his sleeve, and screamed, “Stop that.”
She gripped his sleeve, and hissed, “Stop that.”
Without context around it, one could build a scene simply around the word “murmered,” “screamed,” and “hissed.” In the first sentence, it may denote a sense of intimacy. In the second, a violent scene, where she tries to stop him from doing whatever, and in the last, maybe, a threat. Incidentally, hissed and murmured are both synonyms for the word “whisper,” but as you can see, when they are used, they do NOT convey the same meaning! My point being that synonyms cannot be substituted ad hoc into a sentence without altering its meaning in some way.
Word choice is important, because it can completely change the meaning of the sentence entirely. As a writer, it is your responsibility to convey what you mean as clearly as possible. Your readers will appreciate it!