Apple's MacOS Server has a 1.5/5 rating on the Mac App Store
IMHO, the direct competitor of Server.app in the "SMB office server" use-case is actually a Synology NAS appliance. Synology's set of first-party OS packages has 1:1 feature parity (and then some) with every function Server.app either has, or used to have.And that's the key-word here: appliance. A NAS is a standalone box that receives automatic updates, is 100% remote-management enabled by default, can be easily reset to factory settings, and can't be messed up by employees who think it'd be neat to run local native apps on it, "since it's a computer just sitting there."Plus, since a NAS isn't going to be doing any desktop-OS things, the software for it can be slimmed down enough to run on lower-specced hardware, making the appliance itself much cheaper than the sort of machine required to run Server.app smoothly.No SMB office-manager who needs this kind of functionality these days would buy a Mac or PC, to set up server software on it and leave it sitting there headless in the office. They'd buy a NAS.And, IMHO, that's why Apple haven't kept Server.app up to date. There's just no demand for it any more. Not because of the cloud (which is mostly a complementary use-case) but rather because this software-solution vertical has now evolved into a turn-key hardware-appliance solution vertical. And it's one with slim-enough profit margins, that Apple doesn't want to compete.