The reason so many shells were involved, was because most of them went in the drink, not the Bismarck.
With guided sea-skimming missiles, fewer weapons and hits are needed.
I just don't understand why so many are so enamored of a platform with such a short stand-off to deploy its main weapons system. This is the core of the inherent superiority of carriers - keep the high-value platform far away, and send the lower-value platforms in harm's way to do the damage.
There aren't too many or any sea skimming missiles that have the warhead that can penetrate 16 in of armor plate. They have a hard time dealing with 4 to 6 in as it is.
Most of those shells were hits and devastated the ships upperworks. Many skipped across the water and still hit but from the side. Ballard's expedition revealed that the Bismarck's citadel was penetrated by only four shells. ( 2 from Prince of Wales/Hood and two from KGV/Rodney engagements)
When nations stopped building battleships, they also stopped building weapons that could sink a battleship. The vast majority of the sea-skimming missles and air-dropped munitions would do little else but prompt an early "sweepers" call. Just the presence of a BB on the scene would calm down conflicts real quick. I truly believe that we are lessened by their absence.