The ball carrying position is something that often varies massively between different players. This is often caused by differences in height, age and flexibility.
There are a few large benefits to getting the ball in the carrying position shown in the video below.
The first of these is the ability to dribble the ball without constantly looking at it, this allows the player greater ability to spot passes as well as run into space.
The 2nd benefit is that the position allows the player to most options both in terms of dribbling and passing angles, this makes it far harder to defend.
One of the most common issues you see is a player that instead carries the ball almost behind themselves attempting to protect the ball using their body. While this can very effective at certain levels it leaves the only real passing option as down the line and at a certain level will be easily defended due to the lack of options it provides.