I think this might be one of the reasons zombie a apocalypses are so popular because it gives a plausible reason for why large groups could be just as failure prone as small groups, as well as a plausible reason as to why the survivors don’t just immediately restart society considering the infrastructure, power stations, and factories don’t just disappear but require the knowledge and logistics to run or maintain them and some essential people might have been turned into zombies, plus the risk of attacks while doing maintenance or going out to run it.