Many things are harder than they seem.
Sure, tons of people want to write a book. Actually sitting down and bringing a story idea to completion is an entirely different thing. It's a lot harder to write a book than to have a great idea. Another thing that is harder than it seems is getting a book published. When I wrote my first book, I had visions of people knocking on my door, begging to publish it. Yeah, it didn't happen quite that way. Lots of things have to come together in just the right way in order to get a book published. And these things are after the book has been written.
It starts with revisions. An author who writes a book has to be willing to revise in order to get a book published. So, great, you think you're willing to revise. But how do you know what to revise? It takes finding the right person to give you feedback. Finding someone who isn't afraid to tell you what needs work. And trust me, finding the right critique partner isn't easy. It takes luck. But smart luck (which I'll come back to).
Okay, so you revise your story. Then what? Well, you have to find the right advocates for your book. If you go the agent route, your agent has to believe not only in your story, but in you. Agents get lots of submissions. Actually finding the right agent takes a bit of luck. But once again, smart luck.
Ditto an editor. Finding that right editor at the perfect publishing house is a lot like throwing dice. Except...right, the smart luck thing.
So what do I mean when I say smart luck? Let's first think about the critique partners. Is the best way to find one just to randomly show up to a critique group and begin reading your story? Well, it's a start. But every critique partner isn't for every person. As you're getting your toes wet, take note of who you actually seem to click with. Whose input you truly value. Take chances and go from there.
On to the agent. Sure, you can blind query. You can look up every single agent and send the same letter, maybe customized with their name, to every single agent. Finding an agent this way takes a whole heck of a lot of luck. Insert smart luck. Which agents really will mesh with your story? When you get rejections, what are they saying? Are they offering invaluable feedback? If so, take it!
The same thing goes with an editor. Getting the right editor at the right house is a tricky business. It can seem impossible at times. But tipping the scales to know the business can make all the difference in the world.
So yeah, the whole business of publishing has a ton of luck involved. Do everything you can to tip that balance of luck to your favor.