Except for helping the 6 or so billion people in their daily lives, but hey, the iPhone would be 'better' if it just had 'bash'?
Read your email lately from bash?
Didn't think so!
Now, I use pythonista as a python-shell. Being able to chain a couple of commands and fix a good-enough solution saves a lot of time in many cases such as web scraping on-the-go.
I know this may be an extreme use case, but if iPad is going to be a laptop replacement we need to be able to get a way to speak with it without immidiate access to a laptop.
It's not a false equivalence at all.
The necessity of lower-level technology in the creation of higher-level technology does not imply that the lower-level technology is somehow 'better' or 'superior'.
You are using a UX right now to read and respond to this.
It's crazy to posit that 'UXs are inferior'. Positively wrong.
In the vast majority of cases, UX's are superior to shells. Maps, news, social media, browsing/buying things, listening to music, making music, photo editing - there are actually very few use-cases wherein the shell is advantageous. Even emacs is a UX of sorts.
GUI:s are superior for the specific (limited) use cases they are designed for, inherently since they were designed to excel at those use cases. They are however less optimal when you want to diverge from those use cases and create something new. This is where malleability/modability comes in, and where CLI:s, bash, scripting, programming comes in, and you can't use limited-scope apps for that.
All tools are best at what they were designed for, I agree with you there. I'm however not sure how I in your mind was wrong before. The two are intrinsically bound, but it's undeniable that apps can't exist without tools, but tools sure can exist without apps.