After going to see Creed with my cousin I was interested in re-watching the Rocky movies. I had seen them on TV when I was a wee little thing but I was too young to pay much attention. But I watched Rocky I and Rocky II and I was surprised at how resonant Rocky II is.
The theme of Rocky II is success after success. Rocky struggles to find a job after he can't make it in commercials. He sells his car, flails around, and finally decides to fight again after trying to retire.
It is NOT always easier to succeed after you have succeeded. If getting a book published in some form is considered a success, what do you do after that book? Mostly try to get another one out. Books come out fast these days. Whether traditionally or self published. And to stay on the radar more books have to come out. But getting more books out doesn't mean they will be a success.
One book published doesn't grow a career and that's what publishing is. Well, to be fair it's always been that. But few authors have the luxury of going seven years between books anymore. Now it's a book every year. Two years at the most. Maybe a little longer of you have an understanding traditional publisher and a back catalog.
One book is no longer a success. It's about the success after success.