I don't think Rust can do much about this, since that's an installer provided by Microsoft, and I bet it has licensing requirements that forbid remixing it into a different product.
You could use the -gnu toolchain instead of -msvc. It should be able to work without Visual Studio (although you may have issues with compatibility with C deps and other tools that assume MSVC).
It’s because the official offline installation guide is missing a certificate, which causes the installation to fail.
I don’t know if VS2022 has fixed this issue, but it still exists in VS2026 Build Tools. It’s an installation problem — the very first critical step in using the software — and it still hasn’t been resolved. Such sluggishness is truly something only Microsoft could pull off. This is a serious bug, a very serious one, yet it’s being treated so lightly. The people responsible for developer relations are doing a terrible job.