I haven't read The Road but cannibalism as an alternative to starvation has happened without a global catastrophe, even when people were stranded on a boat or a mountain. As depressing and upsetting a thought as it is, cannibalism does happen when people starve.
(When I visited Nantucket, I was told the story of the man who survived that whaling tragedy. He remained a recluse in his home (tower?) apparently that was always stocked to the gills with food 
)
Anyway re SF, to each their own but personally I expect a minimum of realism - an overlap with what I know about the universe and human nature. What we see everywhere when power structures collapse is difficulty to meet basic needs like food and clean water, and a rapid return to lawlessness & savagery as people realise everything is there for the taking and there will be no consequences. The struggle to come up with a new power structure, to provide safety for loved ones. NOT sitting around all day bored and whinging about lost comforts of air conditioning like pampered children.
Off the top of my head, apocalyptic & post-apocalyptic books that were far superior to Station 11:
The Passage by Justin Cronin
The Day Of The Triffids
Cloud Atlas by David Mitchell
Flood by Stephen Baxter
World War Z by Max Brooks
The Postman by David Brin
And the few I have read that were at about the level of Station 11:
On The Beach by Neville Shute
The Girl With All The Gifts by Mike Carey