What makes a book 'good'?
Is it the quality of the writing, entertainment value, sales, critical acclaim? For a publisher it's more likely to be whether the book has made a profit for them, as may some writers.
Another way to ask the question is 'what is wrong with a book that entertains you, no matter how bad the writing'? Or, more cynically, can ill-educated people judge how good a book is?
Lots of questions, no answers.
I don't know if we can ever answer the question of what makes a good book as it will always depend on the reader's own judgement, this is art after all.
Even if we take books that have stood the test of time, can we really say that they are 'good' books. How many 'good' books have never seen the light of day in any period of history you care to mention. Do we really have the 'best' literature from the 19th century, or just the literature that was printed in enough quantity to survive?
Can we really say that the best books get published in the first place?
What IS a good book?