Oh? Let's replace "Arch" with "Gentoo" in the article and see if these claims sound familiar:

Gentoo Linux is a great distro for those who want to learn everything about Linux. Because you have to install everything manually, you learn all the bits and pieces of a Linux-based operating system.

Gentoo is the most customizable distribution.

Gentoo also one of the best rolling releases. It’s always updated. Users always run the latest packages.

Gentoo is also known for having excellent documentation. The Gentoo Wiki is my to-go resource for everything Linux related.

What I like the most about Gentoo is that is offers almost every package and software that’s available for “any” Linux distribution

That isn't what gentoo was "all about" at all -- certainly there were ricers who claimed that as an advantage. The main innovation was the much-improved customizability of each package (USE flags), something I would note Arch still does not have. There were ancillary benefits of being a source distro like interesting cross compiling use cases.

full disclosure: used to be a gentoo dev / am currently an Exherbo (rolling release/source distro) Dev.