It's not, as any writer who has done this for awhile knows. Each word, each phrase, each sentence is crafted to contribute to the overall work and to keep the writing move. Writing must flow.
But there are other obstacles too. A lack of support is a big one. While family and friends wish me well in my writing and give moral support, that's not really the kind of support and encouragement I'm talking about.
A writer needs a support system; people to help critique the writing and people to spark ideas. Of these two, I am surprised how hard it is to find people to help critique the writing. This takes several forms. One is people to read and review the finished story. But also people to often suggestions to the work in progress. Of all the people who read my first novel in its infinite carnations no one every said my characters were flat or I was too repetitious. No, I had to find out by asking an editor who had rejected my work.
Another obstacle is finding a publisher, assuming you do not want to self-publish. I have a sense that so long as the story or novel is good and you've done your homework regarding what a given publisher wants, finding a home for your work isn't too hard. Does that mean you will always be able to sell your work? No. Sometimes, a publisher just doesn't need what you are selling. But if you look around a look and gauge the market, you should be able to make a few sales.
Of course, doing all that work is time-consuming and can be an obstacle too. It means studying target publications/publishers to ready know what they put into print. It also means reading novels from new writers and online magazines.
Self-publishing has it's own obstacles too. You've got to know the technology so you can provide quality versions of your novel in print and electronically. This can be difficult depending on the service you use.
And even after you learn the process to create the best versions of your work, you have to promote it yourself too. That means a lot of time online getting the word out.
If all this seems daunting, take a deep breath. And focus on the current step of your project. If the story is not complete, finish it. If it is complete, focus on publishing it. Don't get ahead of yourself. Just take it one step at a time.