Are Skyrim and Baldur's Gate 3 immersive sims? If you're asking one of the guys that created Dishonored, yes
It's a complicated question.
The infinite debate about what is and isn't an immersive sim continues to rage on, as one of the co-creators of Dishonored says he thinks Skyrim is one.
Immersive sim, as a genre, is a really hard one to define. I'm not even going to try to define it in any meaningful way for you, I just know that games like Thief, Dishonored, and Deus Ex fit within that genre. It's a type of game that has major qualities of lots of other genres, which is why it can be hard to define. But in a recent interview with PC Gamer, Dishonored co-creator and Arkane founder Raphael Colantonio has shared the bold opinion that he thinks Skyrim is an immersive sim (and that Baldur's Gate 3 is "immersive-sim adjacent").
Explaining himself, Colantonio said "If you really think about it, Bethesda games - or Obsidian games - are very, very immersive sim. The overlap between first-person RPG and immersive sim, it's very blurry. I would say they are less physical than Arkane games, and they're more on the stats, but at the end of the day they totally rely on simulation. Doing things such as fooling a merchant by putting a bucket on its head is definitely an immersive same thing, right?"
I don't think he's entirely wrong there. Immersive sims typically allow you to interact with objects in a game's world in ways that produce unique results, and Skyrim certainly lets you do that, even if it isn't always clear how purposeful some of those moments are. Colantonio, whose new studio Wolfeye just recently announced its Dishonored-looking next game, continued to explain himself, saying, "We always make immersive sims. We've always done them, and we always will. But now, when it comes to the general, you can make an action immersive sim, or you can make an RPG immersive sim. I don't want to speak for Bethesda, but I would be surprised if they say, 'Oh, not at all.' Their games rely heavily on simulations."
On the point about Baldur's Gate 3, a game that also lets you interact with its world in fun and unique ways, though not quite in the same ways as Skyrim or Dishonored, Colantonio said "I do see Baldur's Gate definitely as at least immersive sim-adjacent. If being turn-based still makes sense for an immersive sim. You can definitely see where they were going with that. I loved it, by the way. I loved Baldur's Gate, fantastic game." You and everyone under the sun, Colantonio.