However, this article was created for help in updating a local WordPress installation (in 2012!!) and at that time, the PHP that came with OSX was the mod_php Apache module, that had no direct file access. This is a good thing! FTP is an insecure protocol and sFTP (the SSH File Transfer) should be used instead.

You are correct, as per High Sierra the FTP server software (and also client! software) is removed.