There's no way the genre is dying, I say this because look how long the survival genre was around...
Still going strong, we're just waiting for a good one that puts the right mechanics together to make a decent game.
The same is true for Battle Royale if you ask me.
The market is VERY saturated these days with Pubg & Fortnite clones, mainly because they think any game with microtransactions will somehow just make money. No. The game needs to be fun & have a competent development team. (Hence why PUBG has significantly less players & 500,000 negative reviews)