Writers are warned, with good reason, against relying on cliches and stereotypes when practicing their craft. Cliches are ineffective, regardless of their accuracy. Stereotypes hem characters into stasis. Both are lazy.
Once upon a time, the phrase "madder than a wet hen" was a novel way to describe anger. It was probably funny the first hundred or so times it was written. (Especially to those who have actually seen a wet hen.) Now, it falls limp on the page and doesn't truly express the ferocity of emotion the writer wants to convey.
Likewise, expressions like "tomorrow is a new day," and "a rose is a rose," just feel trite and bland, like plain oatmeal. Of course tomorrow is a new day! The calendar says so and we are not Bill Murray. What else would a rose be? Sure, you could say "a rosa gallica is a rosa gallica" but people might think you were having a stroke.
"Madder than a wet hen" is a transparent cliche. The meaning is obvious but not thought provoking. The reader will skip right over it and feel a little ho-hum about whatever is happening in the scene. You've lost the urgency of your message. If the hen is transparent, conversely, "a rose is a rose" is opaque. It just doesn't make sense. Readers may stumble over these phrases with a frustrated sigh. What does that even mean?
Sure, when spoken, cliches can serve to move the conversation along without drawing too much attention to themselves. They let the listener understand your meaning without making them think to hard. People appreciate easy thinking. Most are just waiting for you to stop talking so they can speak anyway.
If you're writing and the words aren't cooperating, feel free to use cliches as placeholders until you can come up with a novel or unexpected way to describe what's happening in your story. Just be sure to make them obvious in your text (ALL CAPS or a different color font) so you won't forget to come back to them during revision and editing. Of course, if you are intentionally making cliche an integral part of a character's...character, then cliche the heck out of them and have fun with it.
Which leads me to stereotypes...
Let me give you a personal example. Think of the stereotypical Alabamian. Maybe you're picturing an ignorant, guffawing, morbidly obese, barefoot, Bible thumping, overall wearing, cousin-marrying, slow-moving, shotgun toting, Paw-Paw/Billy Bob type (or Memaw/Dixie Belle, if you visualized a woman) who barely finished eighth grade and who just outfitted their mobile home with indoor plumbing for the first time. Certainly, that's what most people think of us.
Yes, us. I'm from Alabama and the stereotype is red crayon, all-capital letter OFFENSIVE. I am vehemently opposed to ignorance in any form. I have rarely guffawed. I have never been obese. The only place I walk barefoot is on the beach. I was raised to go to church but, as an adult, I do not subscribe to organized religion. I've worn overalls exactly once in my life and that was because my mother made me wear them for some ridiculous family photos back in the early 80s. I don't know anyone who married (or even dated) their cousin. I admit to not moving fast because...suffocating humidity. I know how to shoot and own several guns which are all kept unloaded and safely locked away in a gun safe unless I'm going to a regulated firing range. If I ever have grandkids, I can assure you I will not be called Memaw. I am educated (went to undergrad on an academic scholarship, paid as I went for grad school). And, my parents remember when some few people still didn't have indoor plumbing...seventy years ago.
I am not ashamed to be from Alabama. Now, that doesn't mean I agree with the current political climate or that the state's place in history isn't generally awful. I do not and it most certainly is. And sure, stereotypical Alabamians do exist. But their numbers are dwindling. So, why does the rest of the country immediately visualize the Paw-Paws, Memaws, Billy Bobs, and Dixie Belles? Because that's what we've been told, what we've been shown that people from Alabama are like. (Do you think those kinds of people don't live anywhere else in the country? If so, you are mistaken and I am embarrassed for you.) You wouldn't believe how quickly latent red-neckedness will rear it's ugly head when atypical Alabamians are presented with this kind of characterization in books or movies.
Subscribing to stereotypes in your writing eliminates the possibility for your characters to grow and expand. You've forced them into a box which is nearly impossible to break down. I know I ranted a bit about the stereotyping of Alabamians...the topic is precious to me. But I'm not the only one. Consider the portrayal of Italian Americans in literature and film. Did you immediately think of Goodfellas or The Godfather movies? Did you conjure up visions of John Gotti outside a NYC courthouse? Al Capone, maybe? I'm guessing you did. What if I told you "fewer than .0025 of Italian Americans belong to organized crime [families]"? Would you be surprised? Mike Delucia, Italian American author and advocate for better IA representation in Hollywood, clearly and eloquently illuminates the problem with cultural stereotypes in his 2022 article, "Hollywood's Mafia Hypocrisy," for Italian Sons and Daughters of America (ISDA).
What about other stereotypes - those which target the BIPOC, Latino, LGBTQ+ communities? Feminists? Hippies? Republicans? If you can identify a demographic, chances are you can identify a stereotype. Where do you fit - demographically? Are you more than the stereotype? You probably are. I am. Mike is.
The point is, unless you are leaning into the stereotype on-purpose (and acknowledging it), you are simultaneously shortchanging both your characters and your readers. Don't let Billy Bob just be a Billy Bob. Let him grow into a William Robert. Don't let Vinnie the Hammer languish in the corner of a smoky backroom just waiting to bust knee caps. Let him be Vincenzo, the doctor who discovers the cure for non-Hodgkins lymphoma. Not to be cliche about it but, break the molds for your characters and change the world. One story at a time.