I’m just going to assume there’s somebody that makes a single part, it’s all they make, but it has to go into every am radio; and that person paid off a bunch of lobbyists so they can keep selling that part.
It’s stupid. For emergency alerts, cell phones are vastly more useful, the Wireless Emergency System is far more featured, cell phones are likely in everyone’s pocket, and the system is as reliable as the EAS is.
Any other justification is stupid, and propping up AM is probably the result of said lobbyists…