Fortnite isn't dying anytime soon. They always like to interact with the players' wether that being events, adding fresh items, or anything else that attracts users. The game is also free to play, which means a lot of people will play it and potentially get addicted to it, which then leads them to spend money on the items. I mean, sure they lose players for a short period, but that is because those people play the game 24/7. Once they take their break, I am sure that they will return.