I hate that expression. Hate it like poison. (Which is why I loved this article on it.)
First of all, it’s pointless to say “It is what it is“. What on earth are you adding to the conversation, saying that? You might as well just make nonsense sounds, for all that you’re adding.
Except that you are adding a tiny little something that nobody’s probably even noticing. You’re contributing a very quiet note of sarcastic despondency. You’re saying, “That’s how it is, and there isn’t anything anybody could do about it, so the fact that we’re even talking about it is stupid.” It’s a sly little nudge toward believing in futility. Sneakily small, so small that if you were called out on it, you could laugh at what an overreaction that was. But it’s true.
Now, there are many things I believe in, but the futility of life is not one of them. So, “It is what it is“? No. No, it isn’t. Not ever.