Ursula K LeGuin was anticapitalist and wrote books to match, often beautiful ones that recognize the complexity and variation of humanity. I’ll always recommend this short story, which you can read for free right now if you’d like. This particular story is the opposite of explicit, though - it’s a complex mix of metaphor and human connection. She does have other much more explicit works, though, like The Dispossessed.

The Jungle was explicitly and viscerally anticapitalist.

There are also many historical fiction books set during socialist revolutions.