Apple had a server, Xserve, along with a server version of OS X. When Xserve and OS X Server were discontinued, they moved the server functions to an app that could be installed from the App Store. It was discontinued a few years ago.
The masses don’t seem to want to play sys admin on the weekend. A full functioned home server could also cut into their subscription service revenue from people needing more iCloud storage. They seem to be investing heavily in pushing subscriptions to offset slowing hardware sales.
Even with Apple had their own server software, a lot of people who were willing to run a server would setup their own. I ran a Mac mini server for a long time. I dabbled with Apple’s software, but tended to use other 3rd party option that got more love.
