First of all, by “the formula” I mean: Update the entire game with new permanent content and break the rules in season.
Where breaking the rules means: altering existing mechanics in interesting ways (as if it were a bug or an exploit).
Season 4 somewhat followed this concept, and if I’m not mistaken, season 5 will also follow it, but the seasons still feature non-permanent content and the mechanics don’t get to the point of feeling like “cheating.”
It’s a good idea because Eternal mode currently has a problem: Players are asking for stability at the same time they’re asking for content (surely they are not the same people, but they are two groups of eternal).
Focusing on permanent content should create a direction a little more stable (you create a tower instead of constantly demolishing a house) and modifying a mechanic in season should give enough room for experimentation and craziness.
Seasons don’t need exclusive content, they just need to be fun… and there’s nothing more fun (arguable) than feeling like you’re breaking the game.
Context: I’m a seasonal player, not an eternal one.
Diablo 3 made me like seasons at the time and I didn’t like the idea of seasonal exclusive legendary items.
I played Diablo 3 from 2012 to mid-2020.
Remember that the season that “revived” (arguable) Diablo 3 was the season of the royal ring (Season 16)