The reason the QWERTY layout was created was due to typewriters. They tried to move the most commonly used letters away from each other to avoid the "typewriter

The reason the QWERTY layout was created was due to typewriters. They tried to move the most commonly used letters away from each other to avoid the "typewriter levers/hands" from locking up against each other when someone was quick typing. Thus, QWERTY is quite inefficient since it's trying to make commonly used letters as far away as possible.