I have kids now and the last game I prioritized to play this way was BoW during a summer vacation. I just hope these grand single player offline adventures wont go extinct until I will get some solid free time again. But on the other hand, I have such a long backlog of "old games" I want to play so I'm not really worried. It's more my kids that will get caught up in the Fortnites of the future and never experience the world building possible.
I think this is more than anything, an app store sickness.
It has spread a little to consoles and desktop, but I can still buy a 100% offline, single player game, which has the main purpose of entertaining me.
It has a story, a point to it, a mystery often, fun things to do which aren't mining or grinding away.
I pay 80 bucks for the privilege, and am quite happy to do so. It is worth it, giving me many hours of entertainment.
Some boast "oh I finished the game first run through in 8 hours" Really? Such players just ignore all the scenery, don't really explore, don't grasp the full mystery, just... fast fast! Gotta get this over with!
I play and take in the scenery, and games like the Last of Us, Horizon Zero Dawn are fun, take 50 to 100 hours to play this way.
Just reading things in-games, clues, discovering how these worlds got this way was 1/2 the fun of the game!
So stop playing on your portable addiction device. Its hold is more devious too, as it is always in your pocket.
Your PC, console, are with you on the bus. At work. In the kitchen.
Return to us, good sir. Return to real gaming.