I can think of few things more useless than organized sports for 4-6 year olds. Teeball, flag football, basketball, soccer, volleyball, whatever - it's all a waste of time. Both for the parent and for the child. In fact, not only is it a waste of time for the child, but I think it's a hindrance, as well.
People over a certain age will likely remember a much greater amount of autonomy in their childhood than today's kids, or even people in their teens and early 20s. They can remember a time when kids were often pushed out the door into the summer sun and told simply to "go play" and weren't expected home until lunchtime or even suppertime. There was a freedom and creativity that came with those two words. "Go play" could mean anything. It was up to you, armed only with your imagination, to decide what that anything would be.
It could mean organizing a baseball game with other neighborhood kids. It could mean riding bikes around town for hours, with no particular place to go. It could mean heading into the woods or a grove of trees (depending on if you were a rural or urban kid) and building a tree house. It could mean hanging out at a nearby playground. It could even mean getting into trouble. The important thing was, it put the onus on you.
You learned how to behave in groups and how to make friends and enemies. It taught you how to work together and sometimes how to lead. It meant that you had to be creative, take chances, and capitalize on opportunities. All skills necessary in adulthood. When you step back and think about it, those unsupervised, playground interactions are stunningly similar to work and social interactions we have as adults.
I grew up with a stunning amount of autonomy, even compared to people ten years younger than me. (I'm 33) I fondly remember spending all day in the woods behind my house, building forts and concocting massively elaborate worlds and stories to go along with them. When my parents would take me into town I'd get to hang out and wander around with friends. Sure, there were plenty of days where I chose to veg out and play video games, but the remnants of my forts and escapades still litter my parent's property. Slowly crumbling evidence that I had a vibrant childhood.
I also played organized sports at an early age. But at 8, 9, 10 years old. We had spring basketball leagues and summer baseball. But I still had those years before, those years to start feeling my way around in this world on my own. And the organized sports weren't that strictly organized. There wasn't a massive support system propping them up and over inflating their importance. We barely had money for anything more than screen-printed t-shirts and hats. There was one coach for the whole baseball team and one coach for 20-30 kids at basketball camp. The one or two kids whose parents drove them to the "big city" to play in Babe Ruth youth baseball were mocked behind their backs. "Who does he think he is, with his full uniform and batting gloves?" It was more fun diversion and excuse to hang out with friends while starting to learn the fundamentals of the sport than anything else. Sure, there were some prima-donna parents who took it too seriously, but they were solidly in the minority.
The kids I see today and the articles and reports I read and hear about how cooped up and controlled their lives are makes me sad.