macOS Default for Display & Native Resolution

This may be more of an educational question, as I know how to get what I want, but to me it seems like a workaround (though maybe it's 'poor wording' or semantics).

I have a 2018 Mac mini, I'm using a TCL 43S525 4K TV as a monitor hooked up via HDMI. I'm currently on macOS Catalina 10.15.6.

If at terminal I type:

system_profiler SPDisplaysDataType

It responds with information about my video and display, including:

43S525:

          Resolution: 3840 x 2160 (2160p/4K UHD 1 - Ultra High Definition)

So the system recognizes my monitor model and the native resolution of the TCL's display. Yet if I go to System Preferences > Display, and select "Default for display", the mini outputs a 1920 x 1080 -- 1080p/HD signal, and the next line from the above command shows:

       UI Looks like: 1920 x 1080 (1080p FHD - Full High Definition)

To me it does not seem correct that "Default for Display" outputs 1080p for a 2160p display?

If I then select "Scaled", and choose the far right text example, the monitor in the config box says "Looks like 3840 x 2160" and I get the correct output from the command.

43S525:

          Resolution: 3840 x 2160 (2160p/4K UHD 1 - Ultra High Definition)

          UI Looks like: 3840 x 2160 @ 60 Hz

Why should I have to "Scale" the output to get to the "Native" resolution?