I don't think children, or anybody without a drivers license should be allowed to ride on the road at all.
I'm massively pro-cycling, but bikes belong either in dedicated infrastructure or on the roads. Roads must not be monopolized by motor traffic — everyone pays for this infrastructure through taxation and it should serve everyone equally well.
Cycling on a sidewalk is also not a good experience for the cyclist, either. When crossing a perpendicular street it's quite a pain to look behind to see if someone is about to turn into you as you cross the road. This is no problem for pedestrians because they move slowly and can usually look back without wavering too much. It's not a concern for cyclists on the road because they have the right of way. Then there are reversing cars, stuff in the way (bins, lamp posts, whatever) and myriad other reasons why cycling on a sidewalk is impractical.
I love cycling and bikes and firmly believe cycling has an important role in getting people around. But it shouldn't be at the expense of people who're walking. Bikes belong on dedicated infrastructure or on the road. If the road is deemed "not suitable" somehow this needs to be addressed by building better roads.
Then you'd better be driving slowly and paying attention if you want to operate a heavy vehicle around where kids are.
> the road is a dangerous place to be
Roads are fine; motor vehicles being driven at speed make places dangerous.
Last week in my city an electric scooter pulled out of a junction - where the light was red - in front of a bus. The bus performed an emergency stop, causing minor injuries that required hospitalization to a number of people onboard. The scooter just continued without stopping. Police are trying to track down the driver, but it seems pretty much impossible (it was privately owned, not rented from an app).
I've also seen countless accidents from people driving at 25km/h across pedestrian crossings, and the car not seeing them before it's too late. Here you are supposed to dismount from vehicles and walk across, but most people do not.
Near my office there is a junction where you can turn left - crossing a lane coming in the other direction - and go up a hill, at the same time the light is green for pedestrians to cross, and cars are supposed to give way. If a scooter is coming along the pavement at full speed, in the same direction as you are travelling before you turned, there is no way you will see it until it's right in front of you and it's too late to stop.
I think its weird that we would let children of any age, with no knowledge of road rules ride a bike around in traffic.
In my small city, it's legal for kids to ride bikes on the footpaths, but in most of Australia its is not. I think its backwards.