I had no luck getting a tourist visa for my wife. We were married in late August 2017. Three weeks later she had a bridging visa to join me in Australia pending a spouse visa application. I am a dual citizen. She lived there until I retired at the end of 2018, when we moved to Thailand. She has applied 3 times for a visitor visa to the US and been denied. She applied a 4th time to accompany me on medical grounds, while I undergo eye surgery at the VA. That application was also denied. The basic reason for denial is "You failed to convince the official you have strong reasons to return". That means, unless she has a job, a letter giving permission for leave of absence, and strong ties requiring her to return, they will deny it. As someone else mentioned. the decision has pretty much been made before the interview, based on what is submitted in the application. There is a huge burden to change the official's mind at the interview. In my wife's case for instance, the questions asked are such that they have no relevance to intent. For instance, "How many cars do you have and where will you park them while you are gone"?
At the conclusion of the interview, the applicant is merely told "sorry" and handed a form letter stating that you failed to convince the official you had strong reasons to return. The letter also states, "You may reapply anytime when your circumstances change". But they will not discuss what circumstances need to change.
My wife's 4th application was in October. The waiting time for an interview was 1 year. The website does allow for a request to expedite for a family member to accompany for medical treatments. I supplied a letter from the Thai hospital ophthalmology department referring me to the VA for surgery. The official in Chiang Mai refused to even read the letter or look at any documents my wife carried. When she pushed them through the window, he said "I did not ask for those" and pushed them back. Then said sorry and walked away. There was no interview.
We are now 14 months into the CR1 Immigrant visa, with no action from the USCIS since April.