While both contain similar sections, you cannot simply publish your thesis as a research article.
Converting it into a journal article has many steps.
The structure of article for a publication is different from the structure of a thesis.
Publishing your dissertation in a journal is, therefore, going to require more work but it can also make you a published author!
In many cases, publishing thesis is often one of the requirements for graduate students to finish their academic program.
Publishing research findings is one of the more important ways to share research data with the scientific community.
In addition to your personal “brand,” how do you want to promote your department and your school?
With a dissertation, you are proving yourself to your committee.
In the USA, a thesis is associated with a Master’s degree while a dissertation is written as part of obtaining a Ph D.
In either case, both documents require a focused approach to demonstrate an understanding of your chosen research area.