The biggest benefit of FAQ markup is taking up more space in the search results. Search engine optimization has turned into a real estate game. The more space you can take up in the search results, the better.
Similarly, the FAQ schema can be helpful for appearing in the People also ask section of the SERP.
With the rise in voice search, full questions are more commonly asked. Utilizing FAQ markup to your page can help make it a source if you are answering the right questions on your page.