copy editors

Copy desk to management: "You turned your backs on us."
But I've been hearing for years from many readers that books published by legacy publishers are filled with typos and errors of all kinds. I've seen it myself. And I wonder what's happened to copy editing as a field.
I have experienced more success as a novelist than I ever imagined. So why is writing every new book harder than it was to write the one before? And how do I keep going despite my fears?