Soaking the barley before cooking the barely helps it cook better and also helps make the barley easier to digest as well.
You don't have to soak barley before cooking it but if you do soak the barely before you cook it the barley will be easier to digest when you eat it and the barley will cook faster and better.
So that's why it's recommended to always soak barley before you cook it.
But you can cook the barley even when you do not soak it first.
Just adjust your cooking time to another hour or so.
But if you do have digestive issues then it's best to soak the barley overnight before cooking it.