There aren't any game series that exist that really need to die, I think. Most of the commonly listed on shit like this - Final Fantasy and Call of Duty - are incredibly disconnected from each other, series only held together by common themes and gameplay with few persistent characters. The Final Fantasy series does not need to die because -it is not actually a series-, it's far closer to being a small subgenre. Think about it - individual games have had sequels, there are no common characters, locations, or much of anything except spell/summon names and some very basic gameplay mechanics. Square-Enix could very easily just give them all their own name instead of Final Fantasy XV or whatever.