@CremeEggThief
It depends on how heavy the rain is and how adequate the clothing is. Proper waterproof clothing can be expensive, especially if you have more than one child to kit out.
That's part of the problem I think. The modernising of our lives and expectations.
Years ago waterproof clothing would have been high up on must have lists. It was expensive back then too!
These days cars, mobile phones, television and all sorts of other gadgets have overtaken that need and expectation.
So, in the case of cars especially, one of the things that makes walking to school difficult is cars splashing through puddles. But if any passengers were kids and they changed to walking...
Decent waterproofs don't cost more than the average phone contract, television/music streaming services. It's just that priorities have changed.
There are all sorts of accommodations that each family would need to make, but many more kids than currently do so could walk to school, in all weathers.