Becky Chambers is a very recent science fiction author, but she's amazing, and the worlds she creates in both of her series are very progressive and creative. Her Monk and Robot series is about a very positive view of humanity in the future where we've figured out sustainability and moved on from what the characters refer to as "the Factory Age". Robots achieved sentience at some point a few generations past, and robots and humans mutually and peacefully agreed that robots could go off on their own. The main character is non-binary, and overall it's a lovely set of books, and I hope she writes more.

Her other series is set in a different future where aliens across the galaxy mostly live in peace, and while progressive values are the norm, there are exceptions which often feature heavily in the plots. Again, lovely series and I highly recommend it.

Honestly, it's not necessary. I hadn't read of Three Men in a Boat first, but was able to figure out enough through context that it didn't diminish my enjoyment at all.