TUIs, in general, are more amenable to keyboard navigation than GUIs are; id est, even if GUIs offer keyboard navigation, they are simply not, on average, as good as those of TUIs. I'm not sure how that is controversial in the slightest.

It's not controversial, just wrong and different from what you were arguing for before about some innate TUI benefit ("mandatory"), which simply doesn't exist.

Now, "on average" does all the talking here, like, even putting the cli vs tui categorization aside (otherwise the "average" would support no nav, just some text flags), you can't really pick a small niche of TUI apps and compare it to the whole GUI, pick the same niche, and then you'd get categorically comparable keyboard support

No, on average, GUIs are simply better for most people than TUIs. Now if you cannot accept that elementary fact, there is nothing more to discuss with you, as we have wholly different world experiences. Having accepted that, TUIs are better than GUIs by some margin. Now, I can empirically show that there is a better benefit to TUIs than GUIS such that if you don't believe it, (wherever you seem to be in the Islamic world, I pity you) thank you, and have a good day. I am not even Muslim and even still I understand a-salamu alaykum.