What makes the modern novel different and, I would say, more interesting than 18th and 19th century novels? Dialogue.
I have just finished reading Gulliver's Travels and it took me a while to read. I have also read Robinson Crusoe in the past few months and the one thing they had in common was a feeling of drudgery.
Why? No dialogue.
A quick comparison of the above two novels and any modern novel will show the difference is speech is rendered. Whereas modern novels have speech marks to indicate words spoken, followed by the ubiquitous said/asked, older novels have far less speech recorded speech and Gulliver's Travels has none at all.
What it does have is references to speech and an account of what was said. It tells, not shows.
Modern literary fiction has much in common with this older style of writing in having very little dialogue and a number of those pieces of modern fiction could easily have been written in the 19th century. Maybe that's not a bad thing, but I can't help wonder if it points to a staleness in literary fiction and it only survives because of 'the empror's new clothes' syndrome.
The point of this post is that the modren novel is heavy on dialogue and lighter on description than at anytime before. It may be that our generation has seen so much more of the world than our ancestors and we need less help to see the world the author is creating. Or it could be that we seek excitement in our lives, a continuation of the hectic pace at which life goes on around us. I don't know.
All I can say is that the key to the modern novel is in it's dialogue. To become successful and proficient in our writing, we shouldn't ignore the other skills that form part of our writing knowledge, but we will need to work on our dialogue more closely than the others.