Mise installs itself as a static binary actually (but it's of course packaged in many registries), and while there are some third party registries it delegates to for some packages (aqua, asfd), most stuff I have installed is either built-in, or from PyPI, npm or GitHub, i.e. directly published by the upstream maintainers. More info: https://mise.jdx.dev/dev-tools/backends/

You'll see that mise recommends installing itself exclusively through package registries: https://mise.jdx.dev/installing-mise.html

pypi, npm, and even github (through releases) are registries.

curl | sh is an anti-pattern. It passes no security check.

Exclusively? No, the very first option is the install script, which downloads and unpacks the correct binary for your OS from the Mise website:

curl https://mise.run | sh

...which is the same way Homebrew is installed too.

There's always the chicken/egg problem of which dependency manager to install first, though. AFAIK there's no "trusted" installed for Homebrew on macOS though I might be wrong.