Comment by goku12

That's a misunderstanding. You can completely avoid the curl bash pattern if you can install the rustup binary and setup the relevant environment variables (like PATH) manually. Everything else, including cargo and various toolchain versions are installed and managed by rustup. And rustup doesn't have as much churn as the rest of the tools. So, rustup can be (and is) packaged for many distributions. That's all that's necessary in practice. They recommend curl bash because it automates all the above in a single script without exposing such lengthy explanations to a beginner.