My son rode 4th through 6th grade, about 1.5 miles each way on quite streets. There were a number of kids who did that so drivers were pretty cautious. Middle school was out of the question due to no safe facilities for the 7 mile distance. Same for high school.
When my son was in grammar school 15 or so years ago there would usually be about 20 to 30 kids who'd ride (out of 310 in 1st - 6th grades). Today that number is zero due to increased traffic on the county road by the school and some of it from a bit farther away and seemingly much less cautious drivers than local drivers with kids at the school. There's been increasing pressure on the city and county to put in a bikeway or MUP along here but they're saying that it won't happen until their regular redoing of the road which is scheduled for 2027.
A nearby suburb began a fairly intensive program of building side paths about 20 years ago. At the time there were an average of 5 kids who'd ride to the middle school. Today that number is over 100 (of 680 students). They have a goal of 80% of students within 3 miles riding which would be about 250. In talks with kids and parents they've determined that the problem is a couple of intersections. They're working on improving them but the county is reluctant to do anything.
One of the grammar schools wasn't doing nearly as well even with a lot of good paths and some traffic calming in neighborhoods. After talking to parents they determined that the concern was primarily one single crossing of a county road directly in front of the school. Parents said that even with crossing guards they were concerned especially since kids would often not leave school until after the crossing guards had left. They installed a tunnel about 5 years ago and the number of kids riding has been growing quickly ever since.