Simple as this - we cycle to school. We live in an area with lots of cyclists, including children under 10 cycling with parents.
I have a helmet camera.
The local police have an online submission tool.
Everyday I'd say about 10% of drivers are on their phones in moving but slow traffic. There have been numerous near misses as a result of "distracted" driving.
I don't need to go into the details of how dangerous this is (if you don't believe me, just Google), even if in standstill traffic the distraction continues.
You are not being unreasonable = submit it to police - it's law, it is safety of you and your and other children.
You are being unreasonable = leave it to the police to catch people themselves.