Because most of the time, the complicated stuff is just a few simple commands chained together.

99.9% of the time, git is easy. You don't need to do everything on the command line, especially when dealing with diffs and merge conflicts. But in my experience most devs who flat out refuse to use it don't understand most of the basic concepts because it's all hidden behind a layer of abstraction. That's why when I teach the basic concepts, it's command line only. At least you know what that big Squash&Merge button does and why you should never click on the big Rebase button on main/master.