Here's at least a couple reasons why...
This is a snippet from a past post I did and explains at least within the trucking industry why there isn't as much CB activity.
at one time, Truck drivers were some of the biggest users of CB's and many if not all CB shops were located at or near truck stops.That's a fact I can attest to from driving trucks over 30 years myself. Now they are few and far between.
Now a days, Many drivers don't own one or hardly ever turn it on if they do. Today's trucks are mostly speed governed so no need to watch for "smokey bear" (except for those 55 MPH communist states), and most trucks have electronic logs so no need to ask if the " chicken coops are open" more drivers use GPS so no need to ask "break 19 for local info".
The company I drive for has over 150 trucks based in Phoenix and I can easily count 40 or more trucks without a CB. Other forms of entertainment has succeeded the CB with today's drivers. The others I asked why they don't turn it on and the most common answer is they are sick of all the idiot base stations shooting skip blaring across what should be the calling frequency that is Channel 19 jamming the frequency up. That's pretty much a direct quote. That should make plenty of you guys out there proud who do exactly that.
Then there is the influx, if not taking over the trucking industry, all the foreigners from Europe, India, and Asia driving trucks who can careless about what a CB is. Then one day soon NAFTA will be fully implemented but at least I have seen many Mexican trucks using CB radios. Don't believe me? look at the reefer trucks with california and British Columbia plates, Majority of them drivers are Sikh's from India, no they are not arabs just because they wear turbans! Look at the trucks with plates from Illinois, New York, New Jersey, those drivers are from all over former Soviet block countries like Bosnia, Ukraine, Armenia, etc. hardly the CB radio truck driving stereo -type from years gone by.
I hope your parked somewhere safe or better yet at home!