Our brains are all hard wired for preference. Like handedness, preference is the method that is most natural, dominant, and requires the least amount of effort. Preference is what you would choose if two alternatives were equally rewarded.
Identifying your preference does not remove the option of using your non-preference, but can give you insight into what may be automatic – your default mode.
Preferences are independent of skill or ability. If you are right handed and you write something with your right hand, there is no guarantee that it will be neat and legible.
Likewise, if you are right handed and write something with your left hand, it’s not a given that it will be sloppy or illegible – with practice and focus on the desired skill of left-handed writing, you could actually get quite good at it!