There are some real differences.

All the homebrew packages have checksums and are versioned in git, so if the upstream website is compromised and a malware installer is put in place of the package, `curl | bash` will just install the malware, while `brew` would start erroring out and refuse to install after downloading something with a different checksum.

You also get an audit log in the form of the git repo, and you also ensure everyone's downloading the same file, since `curl | bash` could serve different scripts to different IPs or user-agents.

I don't think brew does proper build sandboxing, so like `./configure.sh` could still download some random thing from the internet that could change, so it's only a bit better.

If you want proper sandboxing and thus even more security, consider nix.