I don't have any moral judgement on whether it is better to read fiction or non-fiction.
But here's what I know - fiction is harder to write.
Why? It contains more layers of truth.
When you read something worth recommending to others, it's either:
- A. accurate
- B. believable, or
- C. Compelling
Non-fiction can be passable on any one of these levels. Most conspiracies and political narratives only need to be compelling. If it 'feels' true people will ignore whether it is true or if it's believable.
Non-fiction best-sellers, like pseudo-science books, are often believable and occasionally compelling, or mostly compelling but not fully believable. They usually fall down on factual accuracy.
Some non-fiction is just accurate, but whether it's believable or compelling is irrelevant. These are boring but useful books.
Great fiction usually needs to be true on more than one level.
Accuracy - does the narrative stand up, without glaring plot holes?
Believable - is the story told in a way that makes it believable? coincidences work in real life, but if someone gets lucky too frequently, people stop reading.
Compelling - stories that are structurally sound and faithfully told will still get mediocre reviews if they're not compelling. Can you make people feel your truth in their bones?
Not every work of fiction hits all three. You can often get away with just being accurate and compelling.
It takes years of craft to be great at communicating on any one of those levels, let alone all three.