A few dozen "this is what minecraft" should have been games have come out in the last few years. Nothing has the staying power of Minecraft.

Eh, can you name one? There are several "Minecraft could have done this as well" games, I guess, but nothing really stands out as anything like a spiritual successor, or whatever. There's Terraria, but that's not quite the same either is it.

Well, that certainly goes in the "potential risks" section, but it hasn't happened yet, and it's been five years.