"That front page" isn't the front page, it's the release notes for version 7.0.0.
The actual front page has "The Package Manager for Everywhere" as its subtitle (and that exact description as part of its <title>), and that is basically all you need to know. It's a staple for Unix-y power users on macOS (but supports Linux too, including WSL), and version 1.0 will be ten years old next week. You're not very far off from complaining that Postgres release notes don't explain that Postgres is a database.
Yes. Thank you. The link text gives the impression that is the front page and I didn't notice. I'm sure a lot of people don't notice which is the issue I'm trying to point out.
That doesn't make sense. Why do I need Homebrew to install the command line tools of macOS on macOS? Doesn't macOS already have them installed? Same for Linux, etc.
Replace "need" with "want" and it might make more sense?
Homebrew is the Mac equivalent of APT, Pacman, RPM, BSD ports, etc. It's a fairly traditional package manager for software that doesn't come with macOS. "brew install postgresql" installs Postgres into /opt/homebrew, for example.