That's not my point. As it is, week in and week out, over 30% of U.S. adults use AM radio.
There are lots of stations that did not file for translators and who have bad AM facilities or are in markets that today can't support a station.
Any daytimer is going to be unprofitable as a commercial general market station. A few may survive doing religious or ethnic programming, but even those are in jeopardy if they don't have a translator.
Most of the former Class IV stations in metro areas (1230, 11240, 1340, 1400, 1450, 1490) just can't cover enough without high noise levels. A few of those in small markets can make it, but that is a category that is nearly hopeless: high dial positions and low power.
Many regional channel stations licensed or allocated after WW II are so directional that their markets have outgrown them. And even some of the more powerful stations are also so directional as to not cover their metro area day and night.
Example: Cleveland, Ohio. One AM station fully covers the whole market. The others: 850 so directional it misses parts of the market, particularly at night; same goes for 50 KW 1220. 1260, 1300 and 1420 are so directional they miss big parts of the market. 1490 is a (former) Class IV and does not even cover well the Black community it used to serve when I went to work there when I was 13. And 1540, a daytimer, turned in its license.
But that one good station does well in ratings and bills well. So if you look at the viable stations, they still can make money for quite a few years.