All good points but I'm just telling you what I am hearing in the field. Public agencies also lack the manpower to sift thru all the reports and it MAY be necessary to add camera's in vehicle's to prove driver was on the phone. They have unions unfortunately.
The temptation to look at your cell phone is great but in the end spending money to control a behavior is not in the cards for these agencies just yet. They would rather tempt fate since they are reactionary in nature vs proactive.