As far as content caching goes, making it built in to the operation system is a win-win situation. It lessens load on Apple data centers and speeds up downloads/reduces bandwidth for customers with multiple Apple devices.

The current iteration, however, needs some work. On my old Mac Mini, it is constantly complaining that it needs more space. This will become annoying and I'm sure that some people will find this message anxiety-inducing. For me, I have been meaning to find out whether it stops working or if it purges old content when this happens. I hope it is the latter!

It's a lot easier to manage now. If you just need those features, you no longer need to install macOS server. Just toggle a switch in the Sharing preferences.