1. Godfather 2. Apocalypse Now 3. Godfather 2 4. The Conversation 5. ? Coppola created a small handful of ATG films, but the vast majority of his work is surprisingly mediocre IMO.
You aren't wrong, but then again, how many directors make ANY masterpieces? Coppola has 4 masterpieces... the 4 you listed. The top 1 being a film that many consider the GOAT film period. And many consider Apocalypse Now the GOAT war movie. Not bad.
Of course... I just find it odd that there's such a massive gap in quality between his top 4 films and the entire rest of his filmography.