Stretching is important for young basketball players for several reasons.

First, stretching helps to improve flexibility, which can help to prevent injuries by allowing the muscles to move through a full range of motion. This is particularly important for basketball players, as the sport requires a lot of running, jumping, and sudden changes in direction, which can put a lot of stress on the muscles and joints.

1. Not enough agility training.
While working with the youth full time for the past 8 years I've noticed a complete lack of agility in a big chunk of the kids. 
As agility I refer to the ability to rapidly change body direction, accelerate, or decelerate as well as change levels, which is influenced by balance, strength, coordination, and skill level.
Based on my experience, you can't become a successful basketball player unless you're an athlete first, and to be one you need to develop agility.

Several years ago I was running a clinic for coaches at one of the local community centers. One part of my clinic covered teaching the basics of defense. Coming from Europe it was and still is natural for me that zone defense doesn't exist in youth basketball until at least 7th grade for obvious (at least form me) reasons.
I have to admit, I was very surprised when one of the dad coaches started arguing with me about the implementation of zone defense in youth basketball.
Here are a few reason why we CAN'T use zone defense with the youngest.

Adversity has got to be one of the most critical aspect of becoming a high performance athlete/student athlete and eventually high performing member of society.  
Going through adversity teaches us not to give up as well as problem solving which from my observation the youth has a lot of trouble with.

There are two kinds of adversity - mental adversity and physical adversity. What is great about sports is that we are exposed to both of them which allows us to widen our mental as well as physical horizons.

Working full time with athletes of all levels for the past 7 years has shown me a whole spectrum of behaviors under adversity, from players who break down because of sweat in their eyes or by missing 3 shots to complete work horses who perform at the highest level regardless of the circumstances.

In the era of colorful social media, where it is estimated that our brain has to process about 34 GB of data per week, we get used to the "wow factor" in every aspect of our life's.