@Ericaequites agreed that If the school is on a main road my suggestion of diverting traffic would indeed be unreasonable, although a ban on stopping except for disabled would solve the issue you suggest where the school is on a main road.
However, in much of the country small schools are not on main roads. I have twice in my life lived near a primary school and irresponsible (and in many cases frankly lazy) parents make the neighbourhood virtually impassable for a number of hours every day during school term.
In both cases for me the school has been on a quiet residential street, with a free, easily accessible car park about five minutes’ walk away.
Instead of parking there and walking a few minutes with their children, although the head teacher repeatedly requested that they should, parents have crowded the quiet streets causing traffic jams, blocking driveways, and worst of all, in the winter running their engines in the winter to keep warm and in the summer to keep cool.
A recent air quality study was done outside my local school and found the air quality the worst in the entire town. If I had a child there, I would find that very concerning.
In such situations I think my suggestion that cars be banned from dropping or collecting kids from schools, with exceptions for disabled parents, of course, would make good sense.
I repeat that cars crowding around schools is absolutely everyone’s business. Reducing car drop off traffic to disabled only would be good for all concerned, as long, of course, that there is a reasonable and safe alternative for dropping children and walking.