You'll be searching (or using previous knowledge) for what you need to format it as, anyway.
In any case you are focusing too much on mkfs, I can think of plenty of other examples, many of each aren't even portable across UNIX environments.
While GUIs at least can offer navigation and visual cues as means to discover features.
Eg ffmpeg is confusing no matter what, but the cli is particularly obtuse in how options interrelate (or even the format string required for them!). A gui for ffmpeg will naturally have fewer options (less expressive), related features to an option will be grouped by windows, and might even do things like visibly disable options based on current flags set, or even a preview mode.
You could probably get by to a certain degree, when new to the program, on an ffmpeg gui for simple operations; even the most basic action of cli will be difficult just reading the options appearing by 2xtab.
There’s simply a lot more a gui can do to help the learning/interactive process than a cli can (tui is a different story: its just a gui that happens to be in your terminal, and offers the same positives/negatives that any other gui does).
[1] I mean, I know there are some tools to automate GUI tasks, like AutoHotkey, AutoIt, etc., but due to various window-related issues, they are fragile, I've heard.
Not saying that this makes CLIs superior for all uses, of course. Just better for some.
[2]:
On CLI eg I don’t remember the mkfs command for a file system, I type mkfs and hit tab twice.
It could be better though, of course.