I've heard this for years. I never got why people keep saying things they will never do just to add dramatic flare to their dislike of the Xbox brand. I mean, isn't that the real reason to focus first on Sea of Thieves as evidence of this "endless mediocrity?" The only thing endless here is your ignorance of all the different reasons that different people game in the first place, and ignorance of the fact that if what you say is true then you should have already stopped gaming because what you're talking about is already here in spades and you're one of its principle supporters.
If you're one of those people who play Grand Theft Auto or GTA online, Red Dead Redemption 2, Assassin's Creed, have ever played a fallout or elder scrolls title, play Ghosts of Tsushima, God of War, Last of Us, Uncharted, or potentially buying/playing every major new Call of Duty and purchasing battle passes, or are playing games like Destiny, Star Wars Battlefront, Apex Legends (and chances are high you are, or have, done SOME of that), then you are part of the problem you claim to hate so much.
Don't you get it? EvenThe VERY games you highlight, God of War, Ghosts of Tsushima, as excellent representations of gaming done right are precisely the reasons why developers and publishers aim to, for larger and more extended periods of time, get people to occupy and to keep playing games in those kinds of worlds.
Games like this are the bait to hook the fish such as yourselves, to hook all of us, and they work. You are evidence they work.
You think Ghosts of Tsushima isn't headed squarely in Assassin's Creed territory in terms of length, world size and activities? You think games made by Sony, like Uncharted, God of War, Last of Us 2, Spider-Man, Horizon Forbidden West are either becoming or already are more semi-open hub worldish or full open world by accident!? They're slowly conditioning you to be a consumer who is accepting of such longer, service based experiences going forward where you are willing to keep paying more to dive back in and to stay immersed, but it will never mean the experiences people desire go away. They will always exist as trojan horses to introduce the service based option, or to make you believe that's not what you're getting when it actually is. When Insomniac made Sunset Overdrive and they pitched it as they did, what do you believe the purpose of that pitch was when they mentioned the idea of an evolving world that would be added onto? You think this isn't coming squarely to the Spider-Man games as well? It's already here.
Miles Morales and the next gen Spider-Man upgrade was additional on top of this strategy.
What do you think this expansion to Ghosts of Tsushima is all about with the whole new island, extra playable content and even the next gen upgrades? It's a way to get you to spend more money on a game you've already bought and play it for longer, or spend more money upfront on a game you have yet to buy if you didn't get it yet. This is why you have a Director's cut for Ghosts of Tsushima, why you have a Director's Cut for Death Stranding, and you can bet your ass there will be more of them coming to existing games, and then the next big release will take the ideas even further. This is why EA is doing what they are with their special editions for FIFA 22 and other future titles. It's the same thing as what Sony is doing, where you're spending extra for the next-gen enhancements and whatever else you deem worthy.
They've added multiplayer to Ghosts of Tsushima, they added
RAIDS... where do you think they are going with this stuff!? They are spoon feeding you slowly but surely with their ultimate strategy and direction.
Fortnite is endless mediocrity to you, but here you are happily about to go spend money for Season 2 of Ghosts of Tsushima, just like you happily spend on Seasonal content for Spider-Man, and may even be willing to spend on Season 2 for Death Stranding. You think this stuff and Spider-Man DLC and Ghosts DLC is any different from Fortnite's season passes? or Call of Duty's Season passes? They dress it up differently, but they're all the same.
At least Sea of Thieves in all its "endless mediocrity" gives away its latest Pirates Life DLC for free to all existing and new buyers of the game. Ghosts of Tsushima's raids were free and came so quickly because they were always part of plan from the get go. And newer raids will be added in the new DLC. People can't see they're in a form of Destiny game, just with Samurai. Expect newer "dimensions" to explore in ratchet and clank rift apart. This is also why Halo Infinite is a 10 year project. They will add or perhaps open up parts of the Zeta Halo ring, or allow travel to different places in the galaxy.
In conclusion, I don't know why despite all the evidence to the contrary, and their popularity, that people keep assuming wrongly that amazing singleplayer experiences are going away. If they did you could kiss the lions share of the money floating around and responsible for the continued rapid growth of the games industry good bye. Even the most ambitious service based experiences try to lure you in by the promise of some kind of great story or adventure. Without singleplayer stories or adventures the money would be gone from the games industry.
Just like Fallout and Elder Scrolls singleplayer games were the precursor to Elder Scrolls Online and Fallout 76, but it doesn't mean we won't get Starfield or Elder Scrolls VI. It doesn'tt mean we won't get a future singleplayer Fallout.
All this silly crying wolf is for nothing. I've been hearing people saying they were going to quit gaming since horse armor DLC came about. You're still here because you are easy prey. We all are. And the same people who talk trash about GTA Online and Assassins Creed Infinity, will be right on board the next time they show you something that hooks your asses. They will use the singleplayer adventure bait.