If you want to know more about Hoffa and what might of happened, this is for you.

Rating: 8/10 (13 December 2019)

The low score reviews are obviously by younger people who seem to think this is was suppose to be a fictional mafia movie. They don't realize it's pretty much based on the actual story of Hoffa. Thus it could appear to be boring because in reality, life isn't some super exciting mind blowing story. It's dull at times, even for people in the mafia.
While the story attempts to tell you what happened to Hoffa in the end, it is indeed a theory going by what various people have said/done that hinted in real life. In this case Frank being involved in Hoffa's death. While we may never know how he died or where he is, we do know he was very much killed. Many of the people who knew Hoffa gave the opinion of knowing what happened but as they say in the movie, pleading the fifth. Including Frank. His own family seemed to know what he did in real life and that he seemed to know what happened to Hoffa.
Again, watch the movie. It is long but was very enjoyable. Especially when you would see a brief on screen text of various mafia men and how they would be killed/died in the future. Take the ending as what really happened or don't, it doesn't really matter.