Most of you reading this will say, yea, we know Google has said structured data is not a ranking factor. Yea, we covered that before. But John Mueller from Google said in a Reddit thread that while it is not a ranking factor it may be worthwhile adding, because of how it may enhance your snippets.
John said, "Just to set expectations, structured data generally wouldn't be seen as a ranking factor -- it's just the search result that might be shown differently. Sometimes that difference is enough to make it worthwhile though :). Also, think about what it is that you want to achieve with it, don't just do it because it's possible."
John back in 2015 hinted that structured data may one day become a ranking factor but it has not happened yet and probably won't happen in the future.
The way structured data can enhance your search results in Google may make it worthwhile adding despite it not being a ranking factor.
Forum discussion at Reddit.