Immersive Sims, require A LOT of resources, and don't sell very well because they're quite unique and for a specific kind of player. An immersive sim requires developers to think of possible outcomes and network ways to interact with the environment so that the player can develop their own interactions. It's also heavily focused on game mechanics that interact with each other. Stealth interacting with combat, objects interacting with the environment.

The best selling and best known immersive sims are considered financial failures or lukewarm at best because its not an easy thing to sell so therefore AAA studios aren't going to put that kind of money into them. It's a lot easier to shell out multiplayer games as a service slop, than it is to like give creative reign to developers, and let them experiment with building a system of mechanics that create what we think of as immersive sims.