It's completely unoriginal, and it's based off of a mobile game which wasn't too amazing to begin with. More importantly, why is 99.99999% of the Roblox community part of it's fandom? Honestly, an unoriginal Roblox game shouldn't be as popular as Roblox itself. Also, don't get me started on "Piggy inspired" games, because not only are at least half of them horrible, but why are they all copying a game that copied another game? The internet is so incredibly funny. That being said, I do think Piggy is definitely better than Granny in every way, and it really improves Granny in multiple ways, so that might be why it's popular.