Cargo absolutely uses git, or else we wouldn't've had that thing where setting it to use the cli git instead of some reimplementation lead to massive speedups
What I mean is that it doesn’t use git as the source of truth for packages (unless you point at a git repo instead of crates.io). It does use a git repo for the index.
What they meant was probably, that you have the option to rely entirely on using git repositories for your dependencies or even just paths to other projects on your disk.
You can also setup your own dependency registry and only work with that.
I hadn’t heard of this before either. A quick search (miraculously, Google still sometimes works for me) indicates two separate phenomena: one is that HP did intend to insert printed ads when you use some of their automated print options (https://www.computerworld.com/article/2519039/hp-partners-wi...), and the other is that some HP printers are “web-enabled” in the sense that emails to a certain printer email address will automatically be printed, and the default access settings allow spam ads which then get automatically printed (https://h30434.www3.hp.com/t5/Mobile-Printing-Cloud-Printing...)