What is the “savings” one gets by choosing a server install over a desktop?

I’ve been using 18.04 server for several months to host a few services. I’ve recently started diving into Docker and in many of the guides I encounter they give command line calls that use NetworkManager, which is not installed with server. This is annoying to the point I’m asking myself why I’m not using Desktop.

I chose the server flavor mostly because I like the geekiness of the command line. I also figured it is less resource intensive than it’s Desktop counterpart. While I know I can install Desktop and still use the command line, but what am I “saving” by using Server over Desktop, especially if both versions use the same kernel?

If I’m using the machine as a server, how much is Desktop costing me in terms of resources and performance?