We clearly lived in different areas. I was able to witness huge diversity from my own bedroom. My home market was West Palm Beach and the distant market was Miami. When I was growing up, there was a gigantic difference between WOVV in West Palm and WPOW in Miami.
I grew up mostly in Texas and Oklahoma. I'm mostly a Southwestern and Midwestern person. I was able to get CHR's from Tulsa, Oklahoma City, and Ft. Smith, and they weren't much different from one another. KZBS "Z99" in Oklahoma City was more aggressive musically than OKC's other CHR, KJ103, and the Tulsa and Ft. Smith CHR's. Z99, however, never beat KJ103 and rarely even as much as gave it a scare. At any given time, all three markets' CHR's were playing pretty much the same currents in similar rotation. Z99 broke more new songs, but, even then, during the three years I listened (88-91, when it became KYIS), you could probably count on one hand the number of songs it broke that weren't already on people's radars and weren't already climbing in major markets. Most of those that fit that category didn't go anywhere. Think Pajama Party's "Over and Over" as one example. Never heard that anywhere but Z99, and it never cracked the top-40.
I think this is the exception to the rule. iHeart has gutted their cluster in my local market of West Palm. In other markets I follow, Cumulus, for what it is worth, has gutted airstaff too. I noticed this on the Space Coast.
These days, they're gutting everywhere. When my local cluster was bought by Cumulus, live radio from 6 AM to 6 PM was very much the norm. There were a few isolated Clear Channel stations that were clones of other stations and used all out of market talent and a larger number of small market satellite operations, but live radio during the daytime was pretty normal in most markets of any decent size. I like live and local radio as much as the next person, but I can tell you I've heard some really bad talent in the smaller markets and some less than impressive ones in large markets. I'm not convinced the imported talent from larger markets at iHeart and Cumulus makes for better radio today, but I'm not convinced it's any worse either. I know people say nobody turns to radio for immediacy anymore, but I'm also not convinced that's a good strategy nor am I convinced that hasn't been a self-fulfilling prophecy. Cumulus sliced all that local talent before most of us got smartphones. If radio had any competitive edge, it surrendered it before it had significant competition. When I turn to my local Cumulus properties during bad weather, an element we used to have when we were live is definitely lost. If, however, the only viable alternative would be to have the board op who works at the local college radio station stumble through the bulletins and trying to interpret the radar, the TV audio is probably better.