It's a good question, McDad, don't let the "are you kidding" responses get to you.
CoL and drills like it develop intangibles, like drive and determination, aggression ... but not just aggression, a particular kind of aggression that you learn to turn on and off like a light switch. The kind of aggression that is over-the-top but still you're in control of.
And that particular kind of aggression is hugely important in football, where you have to stop trying to bury the guy opposite you the instant he steps out of bounds, or the whistle blows.
So CoL teaches you how to be mean and nasty, yeah, but also how to stop being mean and nasty as soon as the play is over.
That's why teams do it, or something like it. It's valuable.