Why are you entering commands that you read about online without knowing what they do? There’s a running joke that you need to enter rm -fr / to remove the French language from your system; it actually wipes the entire disk mounted to /.

When you know what the commands do, using the terminal is always going to be faster (i.e., more productive) and use fewer system resources than using a GUI. That’s just a fact, sorry if it annoys you when people point it out. Whenever I need to move a lot of stuff around, I will always use mv instead of Thunar (my file manager) even though I prefer a GUI for most tasks.