You can define it however you want to. I’ve not quite got my bearings in this new era. I think I’d rather not make it all about the playoffs, but I’m not sure that’s realistic anymore. I still care about rivalry wins, protecting Neyland, winning the big non-conference games, etc…but I don’t think most fans will value those things much, going forward, if they aren’t accompanied by a postseason berth.
But more to your point, I do believe we’re arriving at the era where, for most SEC teams, 10-2 is a great year, 9-3 is a good year, and 8-4 is a pretty good, but slightly disappointing year. That’s what happens when you make your sport the NFL-lite.