I've not needed chains with winter tires, but even with studs, if you have slick ice and a grade you are not getting anywhere without them. Studs only help on ice, no benefit in snow.
I have tried going up a few things just for fun with studded Hakkapalitta 10s in 4 low with rear locker and ATRAC on, only to slide back to the bottom as soon as momentum was lost.
So, winter tires or not, 4x4 or not, chains are still good to carry.
As for CO, check points and small fines for even trying to go through with improper equipment is the solution, larger fines on commercial that specifically targets the company.
I bet plenty of the idiots are local though. Regardless, a massive fine will only be enforced when something bad happens, which is a bad prevention policy, you need something small enough that no one feels bad writing and enforcing it on the 16 year old driving to school, but enough to suck. Then you need to enforce it with brutal strictness. But that means more officers, and it will not be a day before people start complaining about freedom and government overreach and dumb _______ (pick you least favorite political viewpoint).