Besides, the context is teaching children the practical meaning of seasons changing.

but it doesn't mean anything?

It's a natural consequence of how the solar system is, because of how the natural phenomena we describe with physics are, and for the purposes of a simple explanation for children "less light [during the day, bleeeh 🙄] = colder out" is totally adequate.

you're trying to do something real weird here mate and it doesn't make any sense.