2E was not a "dramatic departure" from 1E. 3.5 was not a "dramatic departure" from 3E. Pendragon 6th edition is not a "dramatic departure" from Pendragon 5th edition. The current Call of Cthulhu was not a "dramatic departure" from the previous one.
@Soloist didn't say that 2e was a dramatic departure from 1e, and 3.5 was a half edition. If AD&D was being published
today, I'm pretty sure people would be calling 2e a half-edition. Also, what Pendragon and CoC do isn't what D&D has historically done and so is irrelevant. Especially since you can point out other games where different editions
are very different, like WoD games.
Questions:
(1) Who decided that a new edition had to be a "dramatic departure"? You?
(2) Where does "dramatic departure" appear in the definition of the word "edition"?
(3) Who gets to define "dramatic"? You?
I think we can consider having a nearly completely different ruleset to be suitably dramatic. 3e isn't compatible with 2e. 4e isn't compatible with 3e or 2e. 5e isn't compatible with 4e, 3e, or 2e.
But that's not the point.
@Blue was suggesting that 5e isn't actually "evergreen" like it's supposed to be because there are differences between 5.14 and 5.24. However, for the most part, the two games
are compatible with each other. You can't build a character where you take the race from 3e and the class from 4e. That's what @Soloist was saying. You
can do that with a 5.14 race and a 5.24 class, though. Whether that character is
balanced is another thing entirely, but it's possible because the rules are
mostly similar.