I didn’t say you have to know everything, just like I don’t know everything in my house and how it works, but I do know how to do basic repairs so I don’t pay loads of money for a guy to come and unclog a drain. I know how to reset my circuit breakers, how to change a fuse, how to change a lightbulb.
That’s what the terminal is. No one here is telling you to write a bootloader in assembly or meticulously study kernel environment parameters. No one advocating for basic knowledge of a terminal likely has knowledge on subnet masks, compilers, or other low level systems that a modern Linux abstracts for you.
But! I know how to update my packages from a terminal. I know how to install a package outside of a repository, or one that’s not listed on my graphical package manager. I know how to export an environment variable to get my software to work how it should.
That’s what “knowing the terminal” gives you. It’s a basic skill that unlocks you from being a mere “user” of a system to an owner of a system. I don’t think everyone will ever need the terminal, but there are people who are replying to me that seem to have a genuine fear that people have knowledge of their computers in a meaningful way.
Knowledge is autonomy for whatever you do, and there’s a reason why the most profitable of systems are the very systems that are locked down abstracted and “user friendly” in all ways that harm a user’s rights and freedoms.