Why has everyone started saying "it is what it is"? And what does it mean?

Solution 1:

A lot of ink has been spilled over this phrase, which seems to have originated many decades ago, but gained popularity more recently.

The phrase, racing through the language, shows no sign of tiring. The first use I can find is in the Newspaper Archive, from a column by J.E. Lawrence in The Nebraska State Journal in 1949 about the way that pioneer life molded character: "New land is harsh, and vigorous, and sturdy. It scorns evidence of weakness. There is nothing of sham or hypocrisy in it. It is what it is, without apology."

Databases show a steady buildup in usage toward the end of the 20th century. A burst of the sentence's activity followed Billy Frolick's movie with that title in 2001. The jam band the String Cheese Incident used it a year later. Gary Mihoces of USA Today examined a dozen uses of the cliché by sports figures in 2004. On Election Day 2004, when exit polls showed the Democrat John Kerry in the lead, Time magazine reported that President George W. Bush, avoiding any show of pessimism to his aide Karen Hughes, said only, "Well, it is what it is."

It is What It Is - New York Times

Note that this article was published in 2006, so if you've only heard the expression being used lately, your speech community may be a bit behind the times.

These examinations of the phrase usually include a fair amount of philosophizing, e.g.

The increased use of “it is what it is” seemed to be a sign that people are increasingly comfortable with “states of potentiality,” which are states that could “collapse” to different actual states depending on the context.

The Hidden Meaning of “It Is What It Is” - Psychology Today

"It is what it is is also a way of expressing philosophical resignation over a disappointment, of saying that the situation just has to be put up with."

New York Times

And while these analyses may be on point, they also seem to me to be making a mountain out of a molehill.

It's not clear to me how this phrase is meaningfully different than older, more invisible clichés like

Oh well
Too bad
I give up
Them's the breaks
Boys will be boys
Let Reagan be Reagan
Let Poland be Poland
I yam what I yam

And on and on and on.

Solution 2:

The use of the phrase has increased enormously since approximately this time last year when Donald Trump used it to refer to the coronavirus death toll in a TV interview. Since then it has been used, generally sarcastically or ironically to indicate that the speaker has lost control of something or has been ineffective at performing some duty.

https://www.nbcnews.com/politics/donald-trump/it-what-it-trump-interview-covid-19-death-toll-u-n1235734