Ehhhhh. I disagree. That's too much of a generalisation. Different people, different interests. Many kids do like to exercise. Many prefer staying indoor.
Reading this, the 2 hours of physical exercise per week in school make a lot more sense now from an physiological point of view.
I always just took them as fun time and some kids took them as annoying burden that should be avoided. I not once thought about that they are necessary to develop my body and motor skills.
I always took Judo training as a near perfect way to improve my movement skills though.
What kids prefer and what they need are not one and the same. A lot of parenting is about teaching kids to go outside their immediate preferences for long-term gain, and to learn new preferences.
https://www.nhs.uk/live-well/exercise/physical-activity-guid...