[dificilis]

I am going to dispute "it is what it is" as a meaningless cliche, because I understand it to have a meaning like:

"We all know that this thing is not ideal, but, for various reasons, we are stuck with how it currently is."

It is acceptable to use this expression if those listening are already aware of the various reasons why "it" can't be changed.

It's more a summary of the situation as currently understood, than an argument in itself.