

For a bit of mindfuck check kdialog : Tool to show nice dialog boxes from shell scripts
Maybe the shell truly is enough BUT in some cases, say you want to help somebody who for some reason doesn’t want the terminal, you can bring the bare minimum of UI to give utility. My favorite example is the file picker e.g kdialog --getopenfilename "*txt" | wc -l as most CLI commands do support a filename as input.
Looks like, I’m not familiar enough to spot obvious differences.