Teaching in a PLI way, just means focusing on fun and inclusivity, rather than competition, which can alienate young people if they are not immediately good a sports. The focus can be more on personal achievement and progress, and working in teams, without constantly being judges or graded by comparison to others. It also has a wider range of props to engage with in different ways: some of which CAN be competitive, but others can be more creative, dancey and artistic, or just plain solo and nerdy, which allows for many more inclusive ways for young people to be accepted for what ever level they are in physically activity.
But why is it good to be physically active?
An article by Public Health England suggests that early engagement in physical activity led to improved physical and mental wellbeing as well as academic achievement and was a good indicator of continuing to do physical activity into later life (which has its own obvious multiple benefits). You can read more about that here.