He’s also looking at the keyboard, so maybe he’s unfamiliar with it. Perhaps when shooting the video they thought, hey, we need that cool clicky sound, and had him use a mechanical keyboard.
But in all, he types fast enough to write Linux.
Typing speed is important for typists. For programmers, I’d say that even a 50-80 wpm rate is adequate for getting your thoughts down on the file and off to the compiler.
He might obviously be in the 80+ range irl.