Yeah, but it's impossible to properly pin w/o running your own mirrors. Anything you install via apt is unpinnable, as old versions get removed when a new version is released; pinning multi-arch Docker base images is impossible because you can only pin on a tag which is not immutable (pinning on hashes is architecture dependent); Docker base images might get deleted (e.g. nvidia-cuda base images); pinning Python dependencies, even with a tool like Poetry is impossible, because people delete packages / versions from PyPI (e.g. jaxlib 0.4.1 this week); GitHub repos get deleted; the list goes on. So you need to mirror every dependency.
> Anything you install via apt is unpinnable, as old versions get removed when a new version is released
Huh, I have never had this issue with apt (Debian/Ubuntu) but frequently with apk/Alpine: The package's latest version this week gets deleted next week.