From my past experience of living in Korea without speaking Korean fluently I discovered that saying few right things is important. Many people there don’t have energy and speed to process and re-combine a lot of English. Instead, you have to focus on few words to deliver the message. Recently, I was reconciling my observations from living in Singapore, US, UK — all distinct, but all places of fluent English. If you can speak a lot does it still matter to attenuate the details? Yes, and for one peculiar reason. Each word is likely to have a synonym with subtly different meaning. And sometimes you might even choose to expand a single word into whole definition or an illustrative example. Yet, it is an impossibility to say two things at once for the same word — language does not work like that! — instead you have to pick one. And when you do that you are dropping all other options for that particular word. It is pure opportunity cost. Importantly, each word is related to others and guides the flow of thought as well as structure of a message or a dialog. Each choice of a word is tied to a multitude of options for this word itself and possibilities for overall structure that could have happen.
When you talk, when you write, the word looks small, simple, a single thing. Compare this to a vastness of possibilities of the words that follow, a sentence, a message, writing, dialog that could have been until you pick that one word. Not so small anymore, isn’t it?