I just realized what a bad movie this was

Having watched multiple times, mainly to learn other languages through dubbing, I was able to analyze the movie in depth. And I have come to the conclusion what a poor film this is. The following are the reasons that I consider this a poor production.
1. It exactly follows the sequence and pattern of Godfather I. It starts with a celebration where guests come to honor the godfather. Deals are made behind the scenes. The family members seal their loyalty at the celebration. There is a hidden animosity between the gang bosses which doesn't come out until the end. The Catholic church is involved in some ways. And the film ends with settling the scores in one moment. It seems that Francis Coppola ran out of all creativity and had to copy the original Godfather, believing that the audience will like it.
2. It tries to resurrect as much vestige of Godfather 1 as possible. So Enzo the baker appears, and so does Johnny Fontaine. The house in Long Island and Lake Tahoe appear. Michael's first wife appears as well as Vito Corleone's birth house. Even the donkey that was used to bring the young Vito away from the men looking to kill him appears. If these cameo appearances are necessary to tell the story, it's excusable, but they have little part with the plot. The producers are only trying to appeal to the audience's memory of the original Godfather I. Francis Coppola didn't do his homework. He was lazy and leaned on the safe success formula, except it wasn't successful.
3. It tries to combine a gangster story with an opera. The opera scene looks like some kind of a music video, mixing music from the opera with dialogues and background music. They had two kinds of music going on at the same time, which doesn't work at all. Why was it necessary to superimpose the opera on the mafia vendetta story, even if the opera remotely resembles the plot of the movie? It seems that Coppola was trying to make an "artistic" film. But a film is a film, and a film must be fun and convincing to be successful, instead of trying to mix art with filmmaking.
4. Francis Coppola confused himself with Michael Corleone. In the director's commentary version, Francis keeps mentioning about his own family involvement with the filmmaking. His father, sister, and daughter were directly involved. His father did the music, and his sister and daughter played two major roles. Coppola keeps mentioning his own family experiences while commenting on Godfather III as if the film was somehow reflecting his own family story. Nothing could be further from the truth. Coppola's family was just an ordinary Italian-American family. Nothing is his family experience resembles Michael Corleone's experience.
5. Coppola was too personally involved with the film. He involved too many of his family members in the film. His family's contribution to the film is questionable, but no one questioned their place because of Francis' status.
6. Coppola tried to make the story relevant to the real-life events too much. The Vatican bank scandal, the Pope's death in mysterious circumstances, and the resemblance of Luchesi to the Italian prime minister were all not credible. Involving those events in the story of the film didn't make the story either interesting or credible. Michael Corleone is not an Italian, but an American, who happened to make a takeover bid for Immobiliare. His connection to Italy was only through Immobiliare, but the film makes him look as if Michael is in the center of the events going on in Italy. And conveniently Tony's opera debut takes place in Palermo. Nonetheless, it is ludicrous that Michael's henchman takes a train to Rome to assassinate an American archbishop in Vatican, hiding a pistol in a box of cookies!
7. Alto Bello's connection with Luchesi is tenuous. Alto Bello has been living in America all his life. His reason for traveling to Italy was to attend Tony's opera debut. Why does Alto Bello have such a close working relationship with Luchesi? It doesn't make sense. How was Luchesi involved with the Mafia business in New York to the extent that he knows about Joey Zaza? It is ludicrous.
8. Michael's plot to make Vincent fake betrayal of Michael is also not credible. At this point, Vincent's acting skill is wanting. The dialogue between Vincent and Alto Bello resembles a scene from The Good, the Bad, the Ugly -- almost comical.

Francis Coppola absolutely ran out of creative juice when he made the film. He was right in trying to name the film The Death of Michael Corleone instead of Godfather III. He couldn't even come close to the quality of the original Godfather film.