Maybe it is because most of our kids learn to ride the bicycle before they are 5, they do a lot of stupid things while playing near the house, when they are to young to do them in dangerous places.
We do have separate bike-lanes at the side of many buzy streets and country road, but on the other hand, cars may pass you so near that the wing mirror hits your handlebars. (Mostly it is a miss because of a difference in hight rather than in width.)
The age-groups that are most likely to have accidents on bikes are the eldery and the 12 to 16 year olds who use their bikes to go to school.
The kids have mostly a 10 to 20 minutes ride both ways.
The danger their is kids riding 3 next to each other, forgetting there are also cars on the road. And kids crossing when the gap between cars is not big enough.
In those cases a helmet might help, but most harm is broken bones and occasionally a hit by a truck where nothing would have helped.
The eldery (65 to 90-something) are more likely to go at a low speed and forget to look over their shoulder when they change direction.
But on the whole the number of accidents is low, (if I may believe the people interpretating the statistics,) and most of the accidents are of the 'a good scare' kind.
We do not have many railroad turned into bike-paths. Most are still in use by the train
My parents have used several of them a few years ago on a biketrip to Paris, France. And found them boring.
(They are now on biking holiday in France, using the smaller roads of the Normandy and Brittany coast, at 71 and 72.)
But safety is important, and while I do not believe in using a helmet on the bike here in the Netherlands on normal roads, I do believe in using one when racing and going up and down hill.
And when slinging I often use little balls that can not do harm, even a direct hit at full speed will not cause more than a black and blue spot, if that. (I have tested on myself.)
Slinging stones can be much more dangerous, so keep to the same safety rules as the bow and arrow competition people, when there are people in the danger zone no stones in the air.
The slinger needs to protect himself as needed.
Willeke