People saying such things lack a certain amount of logic
Even if League isn't "dying", it has been proved that its popularity is decreasing in a steadily increasing rate since less or more 2 or 3 three years ago, said rate being quite fast at the moment, hence why people might think the game is dying
Even if it has been several consecutive years that some people are expecting the game to die, those small groups were precedently composed of players who just got bored and found a better game. Today, even the "veterans" who've been playing since the start are questionning why they are even playing right now due to Riot's recent decisions who got quite questionnable.
Even if the amount of people joining kinda makes up for people leaving, a lot of the playerbase dosen't have fun playing anymore. Tell me, whats the point of a video game who isn't fun anymore for a vast part of the community and that is only going less and less fun?
I'm not saying the game is dying, not at all. Maybe it is, but thats not the point. the point is that people can't neglect the flagrant flaws that are appearing each months in the game and say "everything is fine, move along, people who don't enjoy it are haters". The game isn't doomed, the problem is that it has the potential to be **easily** ten times better for the majority of the players, but we aren't going in this direction at all.