I thought this was "Radio discussions."
That's a fair point, and, like Kelly, I can appreciate that you want to talk about radio the way it is and about the way it will be in the future. I also agree that you seem like you want to learn about the way things work in the business.
Something to keep in mind is that large playlists might've worked at one time because there were fewer stations on-air and fewer alternatives. Prior to the early 1980's, most markets didn't have very many stations. You mentioned you lived near Joplin. So, I'll use the Joplin area as an example. In 1975, Joplin and Pittsburg only had one commercial FM each. Pittsburg had two commercial AM's while Joplin had four. Carthage had an AM/FM combo while Neosho and Parsons had daytime-only AM's. You could likely only hear the Carthage and Neosho stations in Joplin, and, maybe, the Parsons station in Pittsburg. KGLC 910 covered the bulk of Joplin, too. Those were about your only daytime options. At night, you could get WHB and KCMO as well as many of the other distant "clear channel" AM stations of the time, but many of them followed a similar pattern to your local stations because they were in a similar situation. They had a little more competition, more FM penetration, and new music arrived sooner, but their situation wasn't THAT different. Your car didn't have a record player, cassette decks were still a few years from most cars, and 8-track players were expensive.
A little more than 15 years ago, I was working for a company that owned more stations in the Joplin area than the entire city had the day I was born! In the 1980's, what happened in Joplin was happening everywhere. These new stations being licensed started playing to narrower niches. There's a reason you mostly stopped seeing country songs on the pop top-40 charts after about 1983, and crossover country, for the most part, wasn't a thing by the middle of the decade. I mean, certainly, some people who liked pop also liked country, but they found they liked going to pop stations when they wanted pop and country stations when they wanted country. The new stations ran shorter playlists, had less overlap, and the people listening to the legacy stations found themselves saying, "God, this sucks!", and turning them off. Those legacy stations that felt they could compete scaled their playlists back and continued trying to compete, but a lot of them saw their audiences had already gone and went to pursue new niches. Plus, AM had coverage problems in larger market as suburbs grew and metro areas outgrew their coverage, especially after dark. The result was AM becoming increasingly nonviable, and the more narrowly focused FM stations continued their newfound successful formula.