What confuses me about the part of the article you quote is that wifi doesn't really stick out as one of the harder parts of installing Arch; having fine-grained control over how the system is set up and therefore configuring everything by hand is kind of the point! At least to me, it's more straightforward than manually partitioning/formatting the hard drive and manually populating /etc/fstap, especially when you want to involve things like LUKS and LVM. My standard practice if I need wifi is to start with `wpa_supplicant` and `dhcpcd`, and then I can swap to NetworkManager later when I get around to setting up the GUI (which will usually be "post install", after I've rebooted into the new installation). Setting them up sounds similar to iwd (editing one file and enabling two services), which is pretty run-of-the-mill for an Arch installation.
> Of course, installing a desktop environment may result in NetworkManager being installed and NetworkManager will install it's preferred network stack. That said: I don't recall Arch enabling NetworkManager by default, though it is definitely something people would enable when installing a desktop environment (leading to the dueling network managers situation).
It definitely doesn't enable it by default; I'm not really even sure what "default" would mean in this context because Arch doesn't really have an "installer" in the traditional sense. An Arch installation typically will comprise of partioning/formatting the hard drive, mounting the partitions, running `pacstrap` to install things directly to the mounted root rather than to the currently running system, and then chrooting in to manually configure anything else that's needed. I guess some people might consider what you get from the `base` set of packages to be "default", but IIRC that alone wouldn't come with _anything_ to configure wifi, let alone NetworkManager.