That being said I think it is valuable to have a reasonably fast terminal because it's not uncommon to have applications slow down dramatically if they output a lot of information on stdout/stderr while the terminal struggles to render everything.
Input was just so .... immediate? It’s really hard to describe, but it was surprisingly obviou.
I can definitely tell you that while I can't see the actual letter appearing on the screen - the letter on the calculator would feel as if it appeared right at the bottom position of the button, while on my PC the key would have travelled some distance off the ground before I see the letter.
It's not uncomfortable, but I could easily tell the two apart in a blind test would something like that come up.
It's depressing that he's only ever tried for throughput, when that's irrelevant next to latency. And it does have abysmal latency as per your link.
I'm not sure if Kitty is using GPU specifically to minimize latency, but it would be a good reason.