I've never played dodge-ball, but I honestly can't see what it teaches, either. Learning isn't from a single source, and it's not as if kids can't (or won't) play whatever they please, once school is out.
When I was at school, Bulldogs was a popular game. Now, if you want to learn something, THAT was a game you -COULD- benefit from.
The rules for Bulldogs, for those who've never played: Two groups, one at either end of the playing area. One person in the middle. In the first round, the two groups have to cross the playing area, without being tagged. Each person tagged must stop, and is an obstruction until the end of the round. At the start of the next, and all subsequent rounds, the initial person and ALL tagged people so far spread out, before the signal to start is given. Last person untagged is the person in the middle for the next game.
What does this teach, that ALMOST NO other game does? There's no winners or losers, nobody can be unfairly singled-out, you can't avoid seeing the game from all perspectives... It's a child psychologist's worst nightmare!
What it teaches is to think. It's one of the few kid games that stretches a kid's mind, without boring them senseless in the process.
What it also does is devalue "winning". Since there's a constant rotation, and since the requirements are different, depending on what you're doing, the only "victory" is in whether you have fun or not.
What other games do kids play? Fives. Seriously, this game has been credited with producing people capable of winning wars.
Again, a quick summary for those who have never played: Find a wall. A wall with LOTS of rough sections, strange angles, and other nasty characteristics. Next, you need two teams. Each team has one or two players. Using their hands as bats, the teams must alternately swat a rubber ball against the wall, never permitting the ball to hit the floor. Score and serve as for ping-pong.
This game goes back several hundred years, at least, and is credited with being invented at Eaton. What does -this- game teach? Well, its unpredictability and random elements mean that the skill required is phenominal. But its simplicity means anyone who can move can play.
It also teaches something that, again, very few kid games do. That brute force isn't everything. That skill is a matter of awareness. That winning is about luck, as much as skill, making it less valuable than playing -well-.