As Reggie from Nintendo once said, “If it isn’t fun, why bother.”
I haven't played enough to make a judgment about COD in particular, but like you said, this is from Nintendo, a company whose main franchise is a game for kids about a funny little man stomping evil turtles in a fantasy world. It doesn't even have the trappings of something that you can take seriously and use to inform your real life. Nobody would mistake it for anything close to a realistic historical account, unlike COD.
Is Schindler's List fun?
There is more to media and art than whether its fun. Art can be engaging and intriguing without being "fun". I wouldn't call Hellblade: Senua's Sacrifice "fun" per se, but it's definitely a good game.