[Someone]

Way more than “kinda”. If you have a continuous integration pipeline that checks out projects from scratch (as it should), every build fetches all dependencies, transitively.

Even ignoring download costs, a local cache (one of the functions of an artifactory) helps speed up those downloads and,with it, your builds. It probably also helps against getting blacklisted by code repositories.

An artifactory also automatically backs up any libraries you use. That protects against them disappearing from the internet.