What is there goes the neighborhood meaning?

"There goes the neighborhood" is an idiomatic expression used to express concern or disappointment about negative changes in one's community, such as the introduction of unwanted new neighbors or the decline of the area's safety and livability. It generally refers to the perception that the quality of the neighborhood is decreasing due to factors like an influx of people who do not share similar values or standards, gentrification pricing out long-time residents, or increased crime and disorder. The phrase can also be used teasingly, as a humorous way to express surprise or mild annoyance at a new development in the area.