I think sometimes it depends on the area as well , whilst the school dc go to is brilliant for them, there is an area nearby where dc would have to walk through that most of the parents and teacher wouldn't allow. It officially is allowed in ours at year 6 but in reality the school asks why. For good reason because of the area but its gentle and supportive.
If its a parent working issue and the child is responsible then I know it happens but there are maybe 10 at most that do it. (Small school you see the dc coming in and out and the geography means there are only really 2 routes ). Mostly the parents at year 5 or 6 walk them to the road outside the school and stop at the end and watch as they enter the school gate. And do the same in reverse at hometime.
Those that do walk on their own through the dodgy part , frankly it's an unwritten rule that the other walking parents keep an eye on them. Not in a judgy way (everyone knows it's bloody hard to manage working and pickups) but just a watching eye to make sure those dc are safe in the less than pleasant areas.
Whoever is nearest will either walk near them and sort of escort them from a little way away or watch them through the underpasses (that's the main bit because dealers are forever down there). It becomes a bit of a relay with one parent group watching through a subway and nodding to a one on the other side to confirm handover.
Once they get past that bit the Dc are in a town centre with cameras and lots of community security so they get on their way. Before that through the dodgy area is isolated and security can't see them. To be fair the community patrols tend to make a point of being near the entry point to the town from the school at pick up time, it's quite sweet really as it almost becomes a handover from random groups of parents who walk away when they see the community safety are close enough to keep their eyes on the walking dc.
It's not remotely unusual for a nearby parent to glare at the dealers, make sure they walk between them and the walking DC, step in when they try to speak to the children.
Before anyone asks , yes they are definitely dealers they are overt and don't hide it, yes the police know , yes there is regularly violence or inappropriate behaviour , yes we all report all the time. It doesn't change and won't due to the nature of the area so the parents just collectively make sure the dc make it safely through.