No, DE doesn't mean I have a dumb console. It just means it's a bit lighter. I have all services a modern desktop has, I still run X plus a window manager.

I imagine Xfce or even GNOME 3 can be tweaked a bit to be almost equally energy efficient.

I mean I don't have icons on desktop but that's about only miss of feature (that I don't use on windows either). Alt + F2 for app launcher + rest of it in autostart and under few bindings for common ones. If anything it's faster than anything under Windows, although definitely a power user thing.

Also something like XFCE will still get you the graphical things to fondle without as much power usage as GNOME. The problem is really those (especially GNOME) pissing on performance and thus power usage

This is not a text only console. It's how I was using UNIX workstations circa 1990. Boot to a script running startx to run X11 and a window manager (ttwm?).

What was I missing? Probably a start menu / launcher (but I guess it can be installed and run anyway) and a control panel for settings.

Which modern software won't run in such a setup? Maybe dbus? Systemd? I think a lot of GUI software would still run, some won't, daemons and servers probably would.

Is this something for the nerdiest 1% of the nerdiest 1%? Definitely. I won't do that myself because it's too much of a hassle and I'll probably have to revert to a standard DE to run some software I need for work, but it will work, mostly.