As words are languages elements that describe existants or [Non existants objects](Non%20existants%20objects.md) and carry different meaning, having an extended vocabulary allows us to describe the world we're living in with much more finesse and granularity.
Opposed to that, by restricting one's vocabulary, we restrict its vision and understanding of the world and the concepts associated. I.e, the Novlang in George's Orwell's [1984](1984%20-%20George%20Orwell.md) book is restricting language in a way that some key concepts disappear. In Novlang, the word bad doesn't exist, it is replaced with "non-good".