When the average, non-enthusiast of that category can look at it and tell one game from another on more than just window dressing, that's when a genre begins to mature beyond "X clone".
Where I struggle is I feel like there are cases lately where that just ... isn't meaningfully happening, from an outside perspective. In some cases, even, where it seems like the trend has crystalized so thoroughly that aesthetic is the only thing allowed to vary. You have to have this set of features, and that leaves no room for innovation, so just ... don't.
I've seen "Stardew Valley but" so many times, and that seems to be the punching bag of the moment so I won't dwell on that too long, because what actually inspired yesterday's vaguepost and this one was seeing yet another "survival crafting game" that was just like every other damn survival crafting game but now it's on a floating island and you can build solar panels, so we call it "solarpunk" despite it being grounded in a famously imperialist/colonialist genre.
And I feel like that might be the exception to the rule because I can't point to the X that these games are cloning, except perhaps Minecraft? But Minecraft has it's own category of even more shameless clones, so it feels unfair to deny it has at least evolved technologically beyond cubes. Maybe it's just because I'm so allergic to the format, that I'm unaware of its history, and I should just shut up.
I dunno, I have no solid conclusion for this, because I'm sleep deprived, and I was gonna leave this on drafts but another post got me thinking, and maybe someone else can point to what I'm missing.

