I agree while not sure of 'most'. Causing a statement to be a question was taught to me in a college level course for writing. Matter of fact it was suggested to pose several questions seeking the thesis statement. That is not the case always of course.
One of the purposes of this section is for questions to be a writer's prompt. That may come from the answers. Or, one can easily create a hub from the link below the answer window as an option. I have proposed questions that counter a thesis statement or main idea for writing project once or twice. Purpose being to see those counter arguments that my work might should address.
Most usually a question stems from a writing idea. Other than that one example most of my questions are pretty much of curiosity and if that curiosity causes wonder for others. Sometimes it is because I am looking for possible solutions to a problem. Other times it is because I have had or will have a discussion with another and am looking for objective viewpoints. Sometimes it is to discover how emotional something may be. Sometimes it is to discover possibly the why of my thinking through others.