Professional software development needs to include a software Bill of Materials to help track and manage things like this. https://www.cisa.gov/sbom

Yeah unfortunately these numbers don't really allow any conclusions to be drawn at all.

Also they're not really related to supply chain security which is more about deliberate subterfuge. I think the interesting stat there would be how many authors are being trusted typically for each crate.

It would be good to know how these figures compare to e.g. pypi, npm.

I don’t think cargo-deny alone is enough. And many from Rust ecosystem thinks that if I specified version “1”, it will be enough forever. Many tools nowadays are installed by binstall, so binary will be older and older and won’t receive any updates.