It's a wonder that the humanity has survived for so long. Nature is a harsh and unforgiving place, perpetually pulling us closer to death. The only way to live is to fight, keep moving, keep pushing, and always stay prepared. Even then there are surprises--a treasure trove of horrifying curiosities, predators, toxins, and things that go bump in the night. For most of our history, we'd last three, maybe four decades before succumbing to sickness and infection. A simple scratch could cut our lives short. But that was a long time ago, and things have changed quite a bit since then. We have modern infrastructure, water, and electric. Getting water is as simple as turning a knob. There's a vast network of retail stores where we can purchase everything we need. We don't have to work, and we don't have to worry. Everything has been simplified for us. It's hard to imagine going back to a time when we had to struggle just to have enough food to survive.
In a sense, the post-apocalyptic genre was built to remind us how vulnerable we are. A tiny shift in the ecosystem, a single bug, or a rise in temperature could send all of that crashing down--and it likely will, because nature hasn't changed. It's just as terrifying as ever, and we've grown dependent on civilization. We don't know how to grow our own food or raise and slaughter animals. Many of us can barely use a stove. If all of those things were taken away from us, we'd die by the millions.
We should learn how to take care of ourselves without grocery stores and electricity, and the best way to do that is to get scared. We have to see what can happen when we're all on our own, fighting for the bare necessities. That's why franchises like 'The Last of Us' are so important. They use horror to connect us to our roots. You just need a really good concept, something believable and frightening. Cordyceps was perfect. The fungus is a real-life entity, often used in food, as a medication, or as a health supplement. It implants itself in an insect, takes control of its brain, and eventually grows large enough to pierce through its exoskeleton. It'll lead an ant along like a puppet before bursting out of its head and taking root.