> Plus, say a nuclear weapon went off anyways and all the FM transmitters died. Is anyone seriously thinking a lone AM transmitter 2000 miles away is going to help? We had all the communication in the world during COVID and that did nothing to stop people from acting foolish.

This is an interesting assertion. Many, many people acted responsibly during the pandemic, and in a worst case scenario such as what you described, it's even more likely that a sizable population will gravitate to any source of reliable information.

The government is usually the source of last resort for many, many things. Whether it's as a lender (e.g bailouts) or as a source of information (emergency broadcasts), it's at the scope of the nation state where extreme contingencies exist and must be accounted for. I imagine AM radio is perfect for this precisely for worst-cases, e.g where someone might seek to make a crystal radio, but I'd be out of my depth thinking beyond this.

I actually was neutral on this until I read your comment and thought it through far enough to reply, so thanks for that.