One key element is the underdog theme. These kids were from a place not known for rugby. Another is the role of the coach. He guided them. And of course, the sport of rugby itself is a big part of it.
Well, it is a good movie. The story is about these kids who had almost no hope in life. But then they got into rugby. The fact that it's based on a true story makes it even more powerful. It's about their struggles, the training they went through, and how they changed their own lives through this sport. It's a story of determination and victory against all odds.
The Jungle isn't based on a true story. It's more of a fictional account that might draw inspiration from various sources but doesn't directly represent real events or people in a factual manner.