I'm calling it here and now: this absolutely will become mandatory in the nearish future. 100%.
Same as in Europe with the speed regulator thingy in the cars... advisory at first now mandatory in many places.
California is also working on legislation to require cars to be aware of where they are so they can notify the driver if they’re speeding.
Even when they started mandating airbags in new vehicles, it took something like seven years to go into effect so car manufacturers had time to plan. And then they didn’t make cars that didn’t have airbags illegal.
Even the most universally embraced ideas take time to roll out.
It will happen within a handful of years though. Too much potential for control to let it pass...