It takes around a year to get a doctorate using a publication or portfolio instead of traditional course work. Individuals who have not pursued a PhD via conventional means may nonetheless be recognized for their research accomplishments and the doctoral-level expertise they have acquired by earning this degree.
When there is a lot of competition for academic jobs, having a number of publications may be a useful indicator of how far along a researcher is in their career. My experiences with getting my PhD dissertation published are detailed here.  
 

Having to make a number of important choices before turning in your paper's first draft might make the process seem daunting. Finding a'relevant' subject and question is just half the battle; the other half is deciding when to start writing (e.g., after you've collected data and estimated values).
Both deciding where to begin and when the book is finished and ready to send may be challenging. At both the paper subject determination and the when-to-stop stages, advice from more seasoned coworkers and advisers may be invaluable in helping you make the right choices. When the document is handed in, it only seems to have done half the work. At this point, a big 'but' must be inserted:  For your dissertation, this may be the case, since you probably already have a completed chapter.
 

However, for the publishing process, this is just the first step in what might be a long sequence of edits leading to publication in a peer-reviewed journal. From what has been said thus far, some initial benefits of trying to publish a paper even if you don't have to may be derived: When you finish a chapter of your dissertation, you'll have accomplished two major goals: Having started a paper, I stopped for a while to revise the manuscript. In this way, you advance the work of your dissertation. In my opinion, this is one of the main benefits of the current procedure.

There seem to be two possible outcomes after submitting your work: rejection or being given the option to amend your paper. If all goes well and you have the chance to rewrite the paper, you'll find out that the submission procedure was perhaps only the tip of the iceberg. This is the point in the process when we see the most benefits and the most drawbacks, in my view. 
 

Reviewers who are well-versed in your field of study will provide feedback. There is a wealth of further information in these remarks compared to those of advisers, coworkers, or seminar attendees, for example. In that regard, I gained valuable experience in tightening up my writing, organizing my thoughts, and giving my research context within the larger body of work already out there. The reviewer may also provide suggestions for improving your methodology, new experiments to do, or extra dissemination channels to use in order to demonstrate the validity of your findings. Your present paper is probably already much better thanks to all the extra comments, but you can use them to improve future revisions, too. If your manuscript is denied, you may still use the reviewers' feedback to make revisions and submit it to another publication (perhaps even to the same reviewer).

Although incorporating reviewers' comments into your work will almost certainly result in a far stronger final product, the revision process may be tedious. This is particularly true if you have never made such extensive changes to a paper previously. You should remember that this is only one section of your dissertation and that further chapters may be required before you can defend and get your PhD. In order to simultaneously work on a revision and a fresh paper, you will need to rearrange your workload. You may use this weakness to your advantage by adjusting how you work on future papers to avoid it. In my view, this is a significant perk since it allows you to learn and master many tasks simultaneously. Again, consulting with seasoned coworkers and your advisor(s) may help you thrive throughout the revision phase.