I am currently in the process of defining requirements for UGC for a company and yes, it can be very beneficial for SEO.
At a high level, UGC is beneficial because you are passively generating more and more content. All of this is in the language of your consumers which contributes to the variance of keywords for which your site is found.
On a more granular level, one of the most important things to consider is whether the UGC is rendered client side or server side. The only way UGC will benefit SEO is if you will have server side content loaded for the search engines to crawl.