Not at all. Fingerprinted lockfile systems (yarn or otherwise) provide separate benefits from semver: - The potential for deterministic builds. Saying "my syst

Not at all. Fingerprinted lockfile systems (yarn or otherwise) provide separate benefits from semver: - The potential for deterministic builds. Saying "my system will work after update because all of the updates are minor versions" is a big benefit provided by semver, but saying "it will work after update because the bits of the built files are the same" is a lot more assurance. "No Trespassing" signs haven't "failed" because door locks and fences exist; it's just different levels of effort/assurance. - Security/package verification. - A speed advantage in dependency fetching. Using a lockfile, you no longer have to ask the registry for something that matches your semver pattern, or make multiple round trips. For a single package that advantage is negligible, but across multiple packages with shared dependencies, having a lockfile improves the ability to do parallel package downloads and gives your system knowledge of which dependencies are shared much earlier in the process. - Auditability/visibility. If you check your lockfile in and someone else is having problems reproducing a bug, being able to diff lockfiles makes it very easy to see if your environments differ. Since the full tree is serialized in a predictable place, it's easy to diagnose situations like "you're using a different version of package X, which is causing weird behavior because it's depended on by a package we use". That semver's fault; people put '>' without '<' in semver strings all the time, and that's no more a failing of semver than misspelings are a failing of your text editor. Lockfiles also make it easy to identify the opposite scenario: "our installations are identical; must be something else on your system that's causing the problem--maybe check your environment/kernel rev?" Edits: the soul of wit.