How do I install npm? The npm webpage tells me to go and install nvm. At that tells me to use curl | sh .
So using npm for a new user is still requiring a curl | sh, just in a different place.
See for instance...
Setup instructions for Pkgsrc on macOS with the SmartOS people's binary caches: https://pkgsrc.smartos.org/install-on-macos/
Spack installation instructions: https://spack-tutorial.readthedocs.io/en/latest/tutorial_bas...
Guix setup used to look like this but now they have a shell script for download. Even so, the instructions advise saving it and walk you through what to expect so you can have reasonable expectations while installing it.
Anyway, my point is that there are other ways to instruct people about the same kind of install process.
If security shortcuts are taken here, trust nothing else.