When I learned the keyboard, I also learned the history of QWERTY and why it was created.
The QWERTY keyboard layout is the standard one we're all used to. It was designed in the 1870's for typewriters, with the specific goal that the most-used keys be spaced as far apart from each other so the typewriter didn't jam.
It's designed explicitly so your hands will travel as far as possible. Now that keys don't get stuck in the same way, it's quite inefficient, and a layout like DVORAK is much easier on the hands. I switched to DVORAK for a year in college and it was much more pleasant physically, but I switched back beacuse it hurt my brain to switch back and forth.
Enter iPhones and predictive text, which tries to guess what you meant to type as you tap your fat fingers on tiny keys. Through a historical accident, QWERTY is perfect for this use case. Frequently used keys are spaced as far apart as possible, meaning it's easier to guess what word you're trying to type.
I wonder how much better predictive text is on QWERTY than it would be on DVORAK...