I believe Hitler used the Bismarck as a decoy to draw British warships out of the Mediterranean so he could invade Crete.
As I recall the allies had by then cracked the enigma code and knew the Germans were going to invade Crete. The problem for the Kriegsmarine was that they didn't have enough ships, even if those they did have were very impressive. Both Bismark and Scharnhorst were sunk by small fleets of British ships. Both faced their fate alone. Something that should never have happened.
They were at disadvantage any way. Germany's geographical situation did not lend it self very well for a open ocean navy. To Hitler they were sacrificial pawns.