The first pop culture depiction of a zombie came from the 1932 film White Zombie which was a story about a trip to Haiti gone wrong when a guy's fiance is taken to be turned into a zombie. At the time the idea of a zombie was more based on a voodoo idea which was that someone can be turned into an undead servant by a witch. This idea became mainstream due to the US occupation of Haiti, where between 1915-1934 US troops were stationed in Haiti to exploit Haitians. That wasn't the original idea of a zombie though. During the colonization of the Caribbeans alongside the development of the Atlantic slave trade; African slaves were brought to the Caribbean colonies and stripped of their humanity and forced into a system of chattel slavery which would use them until they die. In this time the zombie was someone who wasn't brought to their afterlife in Africa. If the person offended their spirit of the dead by killing themselves they would be left to roam the Earth as a zombie. It's not known exactly how this entered voodoo belief but it's argued that it was brought in by slavedrivers to discourage suicide. Once slavery was abolished with the end of French rule in Haiti the zombie took a turn into being something one is turned into by a witch. This zombie was a parallel to slavery and was a warning about its evils. Despite this the metaphor would lose its meaning in White Zombie and now entered into a majority White American audience where it became a boogeyman from an "exotic" culture. The zombie would become a monster like the mummy, wendigo, or the genie stripped of its meaning and history (The mummies themselves being actual real life people who were stripped of their humanity since Victorian era mummy parties).
While White Zombie was the first zombie film, Night of the Living Dead was the first modern zombie film. Romero never called them zombies (only using the term ghouls) it became known as a zombie film and would start the genre. The first film had a black protagonist named Ben, played by Duane Jones, although the casting was colorblind the movie's theme would change due to this choice. Harry Cooper's antagonism towards Ben and the ending where a militia lead by a sheriff shoots Ben. The other movies in Romero's original trilogy of the Dead would tackle other issues like consumerism and militarism. I feel that zombies are at their best when they mean something to the story, not when they're used as the "bad guy". The zombies in these films were brainless and often posed little threat to the survivors in small numbers.
Zombies have lost their meanings no longer representing anything more than a monster you can kill that'll make you look like a badass. Films like World War Z or games like TLOU and COD zombies feel as if it's to make you feel like a badass and act as if you'll be like Joel if a zombie apocalypse were to happen (This is also a criticism of toxic masculinity in games). Despite that they're still some great zombie media being released today. Modern zombies are undead mindless creatures that have a desire for flesh but also travel in hordes. While there is always going to be slop made to make someone feel all macho, media like All of Us are Dead and Train to Busan show how they can be used to show issues of class disparity and poverty. It's important to consider where seemingly normal pop culture icons came from and how they've been reinterpreted or misinterpreted. It's important to think about the role that we may play in the appropriation of foreign/oppressed cultures.