Earlier quoted context omitted.
Yeah, because that's way faster and more convenient than double clicking on an icon. It is if you happen to have both hands on the keyboard. That said, I usually navigate a GUI file explorer using the keyboard too, so pressing Enter to open a file is even faster. (This comment was submitted entirely using the keyboard.)
Even if you move your hands (gasp) off the keyboard to the trackpad or the mouse that is presumably very close by, typing that command is probably not faster and more convenient than double-clicking.
When copying files from one directory to the other - CLI vs GUI is debatable in terms of speed (I'd still say GUI is faster, but let's assume its debatable). But what if I want 1, 2, 5, 7 and 10th file; not all files? It is remarkably faster in GUI: Ctrl + click files I need and drag+drop. Done. Good luck fumbling around with CLI.
CLI nerds are the most annoying people I've encountered. They're myopically obsessed with their tmux + cli workspace and are not open minded.