Yes, and they sell for 10 cents on the dollar (syndication truism with a few exceptons), and they only have to fill a couple dozen slots, usually with a dozen advertisers or fewer. A radio station, by contrast, has to fill 800 slots q week, usually with 100 or more advertisers.
In addition, those shows are syndicated by companies that combine those older audiences with shows that sell to younger audiences, for a mix that gives advertisers the variety they seek. A local station that does just that format 24/7 doesn't. Having said that, I've been seeing that syndication companies that sell national spots only have been struggling a bit more than local radio in this current advertising marketplace.