last I knew, Debian requires config setup, not optional, not guided. There is no "defaults that work" for a network server. Is this still true in 2023 ?

Your question seems to be presupposing a bunch of things.

If you run the standard installer from a vanilla USB image, you will be asked questions about the config, most of which produce reasonable results if you just hit <enter>. Some of them will fail in certain environments. (No DHCP server? You will need to enter IP networking details.)

If you want to install a fleet of Debian machines (or VM images), you set up a PXE server and a set of answers to the installation questions, or you build an image for direct deployment, or you use the Debian VM image, or... whatever: there are a lot of possibilities that will work.

Most of this has been true for at least 3 Stables.