For the record I really hate the term "immersion" in discussions about games.
If your argument to a game feature is exclusively and only "it adds immersion" then very likely its an element that will not add anything to the game itself at all, will annoy most players because its wasting their time, and is just a bad idea overall.
Ehh... It really depends on the scope of the feature or element.
Immersion is a very broad term and it's often conflated to mean "Realism" when that's not necessarily the case.
Immersion is more about maintaining internal logic than "Realism" (Of course, realism can often help with that because if something works in real life, then it will work in that setting)
In some cases, immersion for the sake of immersion is bad because all it does to the actual gameplay is make it more annoying.
For example, item durability (Especially when this gets "Gamified" so that everything turns to garbage within minutes rather than a more realistic approach where something can would be used constantly for months before seeing a slight amount of wear...). All this does to the gameplay is make you have to tediously go and repair your stuff every few minutes of gameplay.
In other cases, immersion for the sake of immersion doesn't affect gameplay and just helps things feel more believable.
For example, using gun designs that actually make sense and not Bethesda nonsense garbage (That often has crappy animations that make no sense and have you clipping through the guns horribly for no reason). It has no impact on the actual gameplay, but seeing things that actually function and are used correctly makes everything feel nicer to play as you don't have to try and block out incomprehensible nonsense constantly.
Of course, this doesn't mean that immersive elements that affect gameplay are bad, you can have things that are immersive and generate positive gameplay effects.
For example, take the ability to load shotguns with different types of shells. Instead of being stuck using only buckshot/birdshot (Video game's most favourite shotgun ammunition) you can swap between buckshot, birdshot, slugs etc. Affecting the way the gun performs in an immersive way (Since in real life there are many types of shells you can load into shotguns).
Or using the mode selector on AR's so instead of being stuck in full auto/burst fire you can actually select the fire mode you want like an actual AR using the switch that changes between full auto, burst and semi auto (That's often actually depicted on the gun's model in game...) again, affecting how the gun behaves but in an immersive way.
Again, this doesn't have to always be about realism.
For example, if the setting brings up a means for players to be resurrected with actual logic behind the way it works. Then having a character die in the game and be unable to be resurrected using the same means that the game has already made apparent exists and it functions, will break immersion. As it means the game defies its own internal logic. (One of the most notable instances of this was back in FFVII and Aerith's death... Players had been using Phoenix Downs and Life spells all game to revive dead characters and all of a sudden Aerith is dead forever with no answer)
A game is a game is a game. Game elements have to combine to a good experience overall.
A game is a game, but many games have a large amount of effort put into the setting and the story. We aren't playing Pong all the time where it's purely gameplay and nothing else. But we're being told interactive stories.
Part of a well crafted story, is its believability. Things have to make some sort of sense, otherwise it detracts from what is being told.
The more believable a story and setting is, the more one can get immersed in it. So it feels less like you're engaging with a piece of media and more like you're actually experiencing the story from your character's perspective.
