I live in Poland. Wherever the distance to your nearest school is more than 4 kilometers (or 3 kilometers in the early grades), the municipality has to provide transport - which is usually the case only in rural areas. In cities you'll most likely have multiple schools within 1km, which is perfectly walkable even for younger children. The high school I went to was 3.5km away from my home and I was getting there by tram, but if I went to the nearest one it would be 250m away, just like the primary school I went to. Same with kindergarten in fact, but IIRC I wasn't going there on my own back then. I live in suburbs now and the nearest primary school is 700m away - no reason to drive (nor walk) a ~10yo kid to their school here either.

(for the record: primary school encompasses what US calls elementary and middle schools here)

My very liberal definition of "far away" would probably be something like "more than 1.5km" (the distance I was going by foot to a swimming pool as a kid), more if we consider public transport and bikes too - though those of course won't necessarily be viable options everywhere and at every age.