I read the book. I didn't find it particularly good, and I've read a lot of post apocalypse SF. These fall into two categories: "realistic" attempts to examine behaviour in the aftermath of some catastrophe. The most recent one I would recommend is Octavia S Butler's Parable of the Sower.

The second category is nihilistic despairing romance. Anna Kavan's Ice - where the world is smothered in ice - and some early Ballard are in this category. So is The Road (book and film.

The Road is basically ridiculous. Neutron Bombing? Nuclear Winter? Giant Asteroid hit? Plague? Humanity eaten by Giant Mutant Pink Ants? The author doesn't tell us because he simply hasn't thought it through. Unlike most regular hard sf apocalypse writers who usually work our their premises carefully You can pick out the sheer silliness of it all yourself but I just put out a few pointers: 99%+ of the population has died in 10 years but they don't have clothes to wear or a decent tent.

Only two rounds of ammo? Just so the author can set up a fake dilemma.

Farming Humans for Cannibalism? If you have food to feed humans, you would eat it yourself, rather than loose calories.

Leaving the bunker - the height of stupidity. Wait out and try to rebuild. And one presumes that the people who set it up would have a) stocked it with weapons and ammo b) medical supplies. So when the Dolt (we can't really call him a Man) gets shot with an arrow he should have had antibiotics etc so he wouldn't die.

Medical supplies: ditto the Ship. Question - why does he swim back - are there no life rafts or lifeboats left on the Ship? You could carry a lot more supplies safely.

Maddened brigands and bandits: this comes to the heart of the matter, even bandits are likely to negotiate first. They can't afford wounds, loss of members, and may even want to recruit more people into their gang. Safety in numbers.

It's just ridiculous that there is no government at all surviving, or people banding together for skill sharing and mutual defence.

Why would the nuclear family with the dog accept a lone boy into their group? Unless he had skills that were useful he's just a worthless mouth to feed? If you have read anything about people surviving in adversity, without having a rose-tinted view of humanity, The Road is hokum.