I fear the quality of macOS is deteriorating today in the same manner than befell OSX Server.
https://www.darkreading.com/cyber-risk/apple-blasts-mac-os-x...
https://en.wikipedia.org/wiki/Year_2038_problem
https://www.letemsvetemapplem.eu/en/2024/10/19/chyby-v-macos...
.. macOS but with a utility to install apache/ldap/smtp/carddav and caldav.
very useful for a home server.
absolutely no benefit over Linux for the majority of the workloads it was designed to simplify.
It wouldn't really give you much unfortunately, certainly didn't run noticeably leaner.
(I think at some point "server" just became an .app that was available via the app store).
That sounds like a giant customer base, if paired with the right software for personal / small organization web publishing, blogging, and e-mail.
It's a shame that things turned out differently.
It was offered through the 2010s, iOS development had taken off by then, and the last release was in 2021.