“It’s more realistic” is an argument that’s frequently used to defend an assortment of game mechanics. I’ve seen it used to address weapon durability systems, food/water management in many survival games, and even random generation. When you get down to it, it’s a perfectly reasonable justification: so many games are clawing desperately against the walls of the uncanny valley with their visuals, so why should the gameplay get left behind?
It all comes down to the implementation. Take Metal Gear Solid V: The Phantom Pain: some developer (possibly after a very late night, but who am I to judge) decided to throw in a horse that allegedly defecates in real-time. Receiver is an experimental game that uses realistic gun mechanics; you have to pull back the slide, pop out the clip, individually load bullets, slide it back in, cock the gun... you get the idea. The thing is, these mechanics are either fundamentally meaningless and cosmetic (the former), or have games entirely built around them (the latter). Generally, realistic game mechanics are at their worst when they are core gameplay elements that are tossed in as an afterthought.
Regardless of visual style, game mechanics, or anything else, games are effectively cartoons. In games, we can take a leisurely stroll over an entire continent in an hour or two. We can kill thousands of creatures (human or otherwise) with next to no repercussions. We can carry 50 individually-bottled potions and still be able to swing a sword or fire a bow.
The thing is, we’ve come to expect this, even as we ask for more realistic games. If you’re faced with a towering behemoth (or two or three) in Dark Souls, it may be realistic that you die after one or two solid hits (completely ignoring the fact that you magically resurrect after). However, there are so many other systems at play that are entirely unrealistic. You know that you’ll eventually be able to win through sheer persistence, whether that means practicing for minutes, hours, or even days. In real life, that’s not always the case. What about attack patterns, though? I don’t know about you, but if I was a 25-foot tall monster, and some asshole with a sword kept dodging and stabbing me every time I tried to step on them, I’d probably do something different. If any of these systems were changed in Dark Souls, though, it would radically upset the balance of the experience. Fans might start complaining that they kept having to restart due to feeling underpowered or bosses being too unpredictable.
Of course, with the reputation garnered by Dark Souls, such mechanics probably wouldn’t be haphazardly implemented. Consider other titles, though. How many survival games are on the market these days? How many of them have food/water meters? Now, of those, how many force you to scavenge for sustenance every five minutes? Obviously, this could be considered realistic, depending on the person; I know I’ve had my days where no amount of food ever seems to be enough. However, on most days, three square meals are enough, each of which is the equivalent of a couple sandwiches. Even if I’ve been running around all day, I know that I’m not tossing steaks back like they’re candy (*cough* Conan Exiles *cough*).
I guess what I’m getting at is that even when “realistic” mechanics get thrown into games, they’re regularly “game-ified”, whether it’s the timescale they occur on, their importance to your character, or the way they impact the world around you. There’s nothing objectively wrong with this, but it makes it far more difficult to claim that certain mechanics “can’t be changed because that would be too unrealistic.” What matters isn’t whether something is realistic or not; what matters is whether it’s fun. Games contain virtual, imaginary worlds, so why don’t we take advantage of that instead of being constrained by reality? Anything goes, so why don’t we, you know, go with it?