Single player games aren't dying, but short AAA games are. Almost all single player games this gen have ballooned in size and are structured closer to multiplayer games compared to last gen. They've become huge time sinks with tons of replayability.
It's just a general trend the industry is making. If a studio is going to spend years making a game, they want the game to stay popular and actively played for as long as possible.
It's just a general trend the industry is making. If a studio is going to spend years making a game, they want the game to stay popular and actively played for as long as possible.