Ask HN: Why do software engineers talk a lot more than required?

I am a software engineer myself have seen a recurring pattern. A lot of software engineers talk a lot more than required about a technical subject/work project with technical and non technical people. Also, over complicate things and are not to the point. I also think, this is my personal opinion that the smarter the engineer thinks he is, the more he will talk and will use a lot more words and ideas to explain a simple concept and is not really as bright as he thinks he is