Something has legs

Something has legs  is a newer idiom with an uncertain origin. An idiom is a commonly used word, group of words, or phrase that has a figurative meaning that is not easily deduced from its literal definition. Often using descriptive imagery or metaphors, common idioms are words and phrases used in the English language in order […]
from Grammarist
https://grammarist.com/idiom/something-has-legs/