There are obviously levels of this problem. On the worst level (I hope it's the worst) you have people consuming a completely different reality. I'd argue the US has arrived there. The test for having the problem at this level would be if you could ask a population a question with an objective easily known factual answer and have a significant fraction disagree with the answer because of their news diet.
The UK has the problem at a smaller scale. Other western countries have problems with trust in media but I'd argue they don't have the same level of invented reality as the US.
The UK has the problem at a smaller scale. Other western countries have problems with trust in media but I'd argue they don't have the same level of invented reality as the US.