Letting out balls go is a surefire way to improve your pickleball game. You can also look at it in the inverse: hitting out balls is a pickleball error.
Out ball recognition and avoidance is a skill that a 2.0 player can learn as well as any 5.0 player. The key is understanding the percentages of shots from different parts of the court. And also understanding the percentages of your likely results from hitting the balls.
You can watch this video (it is dull but totally worth it if you are serious about getting better).
And you can download the paper file - study it, it is important.
Spend time on this part of your game and you will happily let out balls sail by.