As others highlighted this is not surprising given that Gen Z uses phones a lot more than computers, and writing in one is completely different than in the other.

[Discussion from multiple comments ITT] It's also damn slower to write in a phone screen, simply because it's smaller - you need a bit more precision to hit the keys, and there's no room to use all the fingers (unlike in a physical keyboard).

Swiping helps, but it brings up its own problems - the keyboard application needs to "guess" what you're typing, and correcting mistakes consumes time; you need to look at the word being "guessed" instead of either the keyboard or the text being written, so your accuracy goes down (increasing the odds of wrong "guesses"); and eventually you need to tap write a few words anyway, so you're basically required to type well two ways instead of just one to get any semblance of speed.