If (any of) you are looking at this article to get FTP connectivity you no longer can, but you CAN use sFTP, most FTP clients (I suggest Transmit.app or CyberDuck) allow sFTP connections. In High Sierra (at least) the PHP handling is done with PHP-FPM which does have direct file access, so updating a local WordPress website no longer requires FTP.
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.
