I think a lot of stations would love to have B98.5's success, but if you compete head-on with them you will get less than half of the ratings unless you find a way to do it better. And it's hard to do better than an Atlanta Cox station. And going less AC/more CHR isn't an option because Power 96 and Q99.7 are already fighting over that.
That's why so many folks keep suggesting softer AC or variety hits, to stay within a similar space while offering something meaningfully different and carving out a different audience. The question remains, of course, whether there would be enough money-demo listeners to make it worthwhile.
I suppose Star could do it on the cheap and voicetrack it and/or have a minimum of on-air talent, but I understand why Entercom would be reluctant to do that in a major market on an intown, 100kW or so signal. Nobody wants to waste that on an el cheapo format.
And back to alt--of all the "big" formats, alt is probably the most narrowcasted of them all. Not what you want to put on the air if you want lots of listeners. Most of those listeners would be better served by satellite or online or a bespoke playlist, not OTA radio.