The terminal commands have same idea and structure and apply to the entirety of your system. While it is still sometimes annoying to learn CLI commands of third-party apps (yes, I know of man, but it can be useless without examples at times), commands are generally the same for Linux systems and they cover everything.

Learning vim is like learning Linux terminal again, but for just one task of word processing in one specific application. Why?

With that being said, I'd rather solve most of my problems with GUI applications rather than go into a terminal. I can do stuff through terminal - I know basics of Linux/Unix commands - but just why? For most routine tasks, it is simply faster and easier to go with GUI, unless you are over SSH or just have a terminal-only instance, or unless you're a sysadmin that does it 20 times each day and have muscle memory running in front of thinking what you wanna do.

I know how to update packages through terminal - the thing you demonstrate. But I can also press two buttons in app store and it will all be done for me, so why bother? (Also, you call it three steps, but it's kinda two steps on Debian or other apt-based distros followed by one step in Arch and other pacman-enabled ones? I'm confused)

I'm certainly not gonna use terminal for word processing unless I absolutely have to. And for that, I'll pick nano.

Linux has to get more user-friendly - and it does. Most people are not die-hard terminal fanatics and want to get their stuff done with minimal headache - and that's where it goes and should go. Being vim elitist doubles down on that terminal philosophy that is alien to an average user. And we should not discourage any type of user to try Linux for as long as they are willing to figure truly necessary stuff out.