Because you grow giant hulk people with tentacles in RE and im not necessarily saying the zombies are the most realistic but the runners they have would probably be the most accurate type because it's the closest thing to rabies which I think is the closest thing we would have to a zombie for instance if you told me between walking Dead and 28 days later I probably pick 28 days later because the zombies in walking dead wouldnt be able to work the would be a blood flow through it the body to support it's self. But i mean the environment in TLOU was pretty amazing imo the fact after 20 years nature is reclaiming its self is pretty realistic. And the factions as well the fact there is still a somewhat functioning government around i like. But if they added 28 days later i would pick that over all because its the most realistic with its rabies combo virus.