Half the population claims it's all a hoax and lets zombies bite them because anything else is a violation of their freedoms
Large swaths of gun owners take to the streets, and half of them die quickly because they put more money into the number of guns they had or making them tacticool instead of putting rounds through them or sighting them in.
It gets overly politicized.
The literal collapse of civilization, yet some corners of the government and billionaires are still trying to milk out the last drop of money
I actually think it would be good uniting force for a divided country:
The "it's a hoax" portion of the population will simply become zombies
The "we love guns" portion of the population can now take their life frustrations out on the zombies
The "we need to fix this world" portion of the population will learn to fight too and provide vital aid and supplies to the (likely growing) "we love guns" group
The "we need run away from this madness" portion of the population will just hunker down and play on their smartphones
I think you're a little off on the "we need to fix this world" guys.
Although zombie films / TV series lean heavily into the action side of things, that's just because it's more entertaining than watching people building things, developing tech, doing scientific research.
Remember with COVID 19? Huge numbers of people immediately set out to find a cure, inventing and deploying ways to prevent and monitor the spread, creating pop-in treatment centres, etc.
The game series Dead Rising does the last bullet point with Zombrex, the 24 hour zombie prevention drug, which they need zombie outbreaks to make the drug so the pharmaceutical company starts causing them.
Avenue 5 has a pretty funny scene where a series of skeptical conspiracy theorist types are ignoring a very specific warning, claiming that the people they see dying before their very eyes are an illusion some kind of special effects and each follows to their own death.
Feed, by Mira Grant, is fun because it takes place years after a zombie uprising, but in a world where George Romero movies existed, so everyone knew what to do. It was a catastrophe, but not an apocalypse.
The movie follows a minimum wage delivery driver in his armored car plowing through hordes of zombies to deliver pizza to the safe houses where people are hiding out.
Edit: When he delivers the pizza, the survivors complain it is cold and don't tip. He backs his truck through their security fence, letting the zombies in and drives off to the next delivery.
"No, I am not going with you to a concert in the park! There's a zombie horde out there! We'll get bitten!"
"Hey, even the WHO says it's not an apocalypse anymore. The zombies are endemic now. You can't live your life in fear."
"Your mom was eaten by zombies literally last week."
"Yeah but she had diabetes. There's always gonna be people with preexisting conditions who are gonna be more vulnerable."
"At least wear your denim jacket to make it harder for them to bite you!"
"There was a study in the Lancet that said heavy clothes don't work."
"You know full well that what they found was that requiring heavy clothes didn't work because people just got bitten at the times when they weren't wearing them."
"The author himself said jackets don't work."
"He said that after he was bitten and just before demanding our brains!"
"Okay, sheeple. Oh, hey Mom. We're just heading out to the concert."
"Wait, your mom is here? I thought she was..."
"BRAAAAIINSSS..."
"You LET HER BACK IN after she died and came back as a zombie!?"
"Dude, she's not infectious anymore. She caught it like four days ago."
"That is NOT how this works! What... DON'T HUG HER!"
There's a series called The Bite, it was filmed during earlier quarantine times of the ongoing pandemic and features a bunch of cast from The Good Fight. Is good.