Why do we call a vocabulary a lexicon? Why do we call words verbiage? It seems really unnecessary. Enough people don't know the meanings of the latter words that using them only complicates things. And why make things complicated?
This is an issue I struggle with. I like big words. I happen to know a lot of them, too. I like the way they sound, the way they feel to say. Sometimes they have a nuanced meaning that truly expresses what I want (like "verbiage" meaning an abundance of words). Sometimes, I just like being different and saying anything other than a common word.
That last reason is not a good one. That's the kind of reason that makes communication less effective. If you know a word that everybody else knows and it serves the purpose you need, just use it. The world will be a better place.