I had served on two WW2-era ships during my time in US Navy (one was a heavy Cruiser, the USS Columbus). The Yamato must have been a fearsome sight!
I had been told that the reason Yamato was defeated, was that by the time it was put to sea Japan's air-power had been wiped out. Without planes to defend it against US air attack, it was helpless. If the Yamato had been finished a year earlier, it may have been a very different story! The documentary, while acknowledging that it was US bombers that destroyed the ship, never mentioned the lack of accompanying Japanese aircraft.