League is a "dying game" and that's perfectly fine
The words "dying game" are always thrown around. Use for Yugioh for example. People always call it dying, yet the game as steady releases and is usually fun. However, they aren't the big popular game that everyone wants to play, like Fortnite right now.
So, why is it fine that League is a "dying game". A "dying game" just means that the game is no longer a fad and doesn't rapidly gaining players anymore. It is completely impossible to circumvent, though there are cases where a game lasts long enough that it can have another boom. Pokemon might be an example of this as Pokemon has lasted so long that it now has another young audience to capture, but for older fans the same rules of "dying game" apply.
So, what are the rules of a "dying game" and how they should act? Let's look at Yugioh again. Every year there's some kind of legacy support that comes out. An upcoming set (for the TCG) called Soul Fusion, while still featuring new cards but also contains legacy support for Galaxy Photon. Previous sets and a Jump promo has support for Cyber Dragons. Supposedly, there's going to be support Neo Spacians at the end of the year. Even now, you can see that Duel Links is a thing. What does any of this mean? It means the game is doing things to keep newer players and current players interested while also doing things to keep old players and bring old players back.
What does any of that have to do with League? Not exactly sure. League isn't a 20-year-old card game with a bunch of sets and things it can do for nostalgia. However, it just should be noted that League isn't a fad new game anymore. It shouldn't try to gather new players because that isn't really possible anymore, but instead, mostly priorizie trying to get back old players and keep current ones interested. New players are, of course, still a thing, but the game isn't a new fad and should probably cater more to the niche the game fills rather than trying to compete with fads (in this case, battle royal games).