Essentially the word is gone. In some parts of Australia it is considered very amusing if the word is strung out and extended to rub in the intended ridicule associated with having it said to you. It can also pass as way of describing deceased.
When someone says, “that’s not where it’s at/ what it’s about”, it shows that a person or situation is missing a certain quality. Gooboobootis is the quality of something that is just right.