Huh. I have got the wrong impression, then, from various blogs/articles which suggest never relying on SemVer because it's regarded as as-good-as-useless. Thanks for setting me straight!
And on my team we pin exact versions and use semver to inform the level of scrutiny when we manually update packages. Probably hasn't prevented any issues, but it helps folks sleep at night knowing our code doesn't change unless we tell it to.
