Like most things, realism in games has some good aspects, but also bad ones. The good thing about realism is, that it can make a game feel more like a real world by adding extra detail, which helps with immersion. It can also add more options and interesting decisions for the player. However, if overdone or implemented poorly, it can also make the game tedious or even break immersion.
The bad aspects often appear when people try to mod a game to be more realistic. A great example are survival mods. On the surface it sounds like a good idea. You have to bring enough food, think of how warm your armor is and have a reason to sleep. However, in practice it often turns out as go into your inventory and click a food item every 10 minutes and make a fireplace every few hundred steps, or die. It turns into a busy work with no challenge, until you run out of supplies. It can also actually make the game arguably less realistic when you have to attend to your needs too often and when you see NPCs that don’t abide the same rules as you. When you go through a river in winter, you freeze to death without making a campfire, but when a NPC does it, they are totally fine.
Another way how such mods can actually break immersion instead of increasing it, is not realizing the full consequences of adding such changes. Like making nights really dark, so you can barely see without a torch, but forgetting to address the enemies, who can still see just fine. Having an extra challenge in the form of a freezing river is nice, until you come up with a solution, like laying down a makeshift bridge, and realize the game does not allow that. You might easily keep track of periodically feeding your character, but nobody told the prison guards to bring the player food.
Seeing mods with these problems is frustrating, because it does not have to be this way. Making a game realistic does not mean adding tedious busy work. We can abstract away the boring parts and keep the extra options and interesting decisions. Instead of the game nagging you every so often to feed your character, the feeding could happen automatically, so the player just have to keep track of how much food they have left, preselect the consumed ration size and decide whether to take more food on a journey in favor of other equipment. The game could even have malnourishment as an illness, so that the player shops for a variety of foods instead of just whatever has the most calories per weight.
Fully integrating a new mechanic into a game takes a lot of work, but it is necessary, if you really want to make the experience good. Most people might not notice the absurdity of half naked enemies running around on ice, until they install a mod that forces the player to dress properly.
Of course, realism is usually best realized, when it is part of the game’s core design, instead of tacked on later. However, there is still no shortage of games which try to be realistic and make the gameplay worse in the process. To provide an example, lets take a look at Foxhole.
Foxhole has an interesting premise of making a war simulation, where players do not just the fighting, but also the other important aspects of war, like logistics. Players have to mine resources, bring them to factories, those produce various equipment and that equipment has to be delivered to the frontline, so that other players can fight with it. While fighting, there are a lot things players can do – driving tanks, directing artillery, healing wounded, building bases and even when doing the standard infantry role players can cooperate with two man weapon platforms. Compared to that, logistics is one dimensional with very little challenge. Yet, people must do it, if they want to be able to do the other things. Sure, there are people who will tell you they like to do logistics, but do they really? Is it really the repetitive task that you like doing, or is it just something that keeps your hands busy while you are listening to music or a podcast? Not every game has to make you think, but if it does not require any reactions either, you might as well pick up knitting or painting instead. I bet very few people would do logistics, if they had only the game to pay attention to.
And again, it does not have to be this way. The game would work just fine with AI controlled trucks, that players could order to haul material between a mine and a factory, or a factory and a storage in a major city. Instead of holding the forward movement key all day, players could focus on managing the trucks and manually delivering the currently needed equipment from local storage to the appropriate frontline base.
In the end, game mechanics exist to provide a fun challenge, whether they are realistic or not. Choosing between multiple options with consequences is fun, pressing the same button repeatedly without even thinking about it is not.