tl;dr is useful when a piece of long and bloviating, or when the piece is outright wrong and can be refuted by re-stating the thoughts of the author in fewer wo

tl;dr is useful when a piece of long and bloviating, or when the piece is outright wrong and can be refuted by re-stating the thoughts of the author in fewer works. It's also useful to other users when someone is using it to summarize a scientific or niche post which other uses might not understand, putting the story into layman's terms.