They are not telling you the real reason why we are doing away with traffic signs. It is to do with the fact that congestion has now become so widespread that it is not possible to drive anywhere. If the car is left to stand and look pretty on a motorway, waiting for the end of a rush hour that never ends, there is little point in having a sign that says “slow down!”
Of course, it could be a novel way to deliver population reduction. I mean can you imagine the French being polite and letting an English person turn in front of them?