It's all about investing a little time to learn something that dramatically speeds up your workflow. A mainstream user has no interest in this even if they work with the computer all day. Hackers as computer enthusiasts do.
When you worked on those early computers you either had to be an enthusiast or be forced by an employer to use them :)
GUIs are great for infrequent tasks. TUIs for efficiency at frequent ones.
As mentioned, I started into computing when TUIs were the only affordable computing model.
There is no magic to me about whatever greatness of TUI and CLI.
Arguing with them is like arguing with audiophiles.
When I press F12, does an inspector open? Where does it open? When I select some words, how do I send them to a new tab in YouTube, Amazon, Google or Stack Overflow? How do I open all the links which are within a selected rectangle in new background tabs? Or use uBlock Origin's element picker?
I'm pretty sure this browser is super fast and all is super optimized and a top tier workflow, but mostly in certain limited scenarios.
What did you think of the demos? The sorts of things you mentioned seem like things doable in NYXT based on the demos, possibly even the exact sort of stuff they are trying to make possible. It looks like it's basically Common Lisp with a web browser attached, which suggests it should be fairly moldable too. I have not seriously used it myself though, so I can't say for sure what the limits are.
Not necessarily with Nyxt or keyboard of course.