TFA quotes Bill Joy:

  “[...] you've got to remember that I was trying to make it usable over a 300 baud modem. That's also the reason you have all these funny commands. It just barely worked to use a screen editor over a modem. It was just barely fast enough.”

Oddly, the reason that the vi paradigm has survived in the form of Vim/Neovim, Evil, Kakoune, Helix, and probably more, is that the interface that vi was optimized for (the QWERTY keyboard without a mouse) turns out to still be an extremely efficient interface today.

For complex interactions, we still haven't invented anything that would supersede what is effectively a typewriter from the 1870s. Look at HJKL in the home row on this Sholes and Glidden: https://commons.wikimedia.org/wiki/File:Sholes-Glidden_1874....